Activation of natural pozzolans

ABSTRACT

A method of manufacturing an activated pozzolan composition includes: (i) grinding a natural pozzolan, alone or with another mineral component that is not cement clinker, to form a finely ground pozzolan component having a first d90 in a range of about 10 μm to about 45 μm and a first d10 less than about 5 μm; and (ii) blending, without intergrinding, the finely ground pozzolan component with a coarse particulate mineral component comprised of coarse mineral particles not interground with the fine interground particulate component, the coarse particulate component having a second d90 greater than the first d90 and a second d10 greater than the first d10. The natural pozzolan can be one or more of natural pozzolanic deposits, volcanic ash, metakaolin, shale dust, calcined clay, trass, and pumice.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application is a continuation of U.S. patent application Ser. No.16/944,587, filed Jul. 31, 2020, which is a continuation-in-part of U.S.patent application Ser. No. 16/241,994, filed Jan. 8, 2019, which is acontinuation-in-part of U.S. patent application Ser. No. 15/862,854,filed Jan. 5, 2018, now U.S. Pat. No. 10,233,116, which is acontinuation of U.S. patent application Ser. No. 15/332,468, filed Oct.24, 2016, now U.S. Pat. No. 10,494,298, which claims the benefit of U.S.Prov App No. 62/245,399, filed Oct. 23, 2015. The disclosures of theforegoing patent applications are incorporated herein by references intheir entirety.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The invention is generally in the field of hydraulic cements,supplementary cementitious materials (SCMs), blends of hydraulic cementsand SCMs, and methods and apparatus for manufacturing hydraulic cements,SCMs, and cement-SCM compositions.

2. Relevant Technology

Supplementary Cementitious Materials, such as coal ash, metallurgicalslags, natural pozzolans, biomass ash, post-consumer glass, andlimestone, can be used to replace a portion of Portland cement inconcrete. SCMs can yield improved concrete with increased paste density,higher durability, lower heat of hydration, lower chloride permeability,reduced creep, increased resistance to chemical attack, lower cost, andreduced environmental impact. Pozzolans react with calcium hydroxidereleased during cement hydration. Limestone can provide a filler effectand accelerate cement hydration. Some SCMs have self-cementingproperties, an example of which ground granulated blast furnace slag(GGBFS).

Portland cement, sometimes referred to as “cement clinker”, “ordinaryPortland cement”, “OPC”, or “cement” is typically the costliestcomponent of concrete. OPC manufacture is very energy intensive,requiring the burning of large amounts of fuel, which produces CO₂ andother pollutants as combustion byproducts. Calcining limestone (mainlycalcium carbonate, or CaCO₃) also releases process CO₂ when convertedinto lime (calcium oxide, or CaO). In fact, the manufacture of cementclinker contributes an estimated 5-7% of all manmade CO₂. Despite anabundant supply of lower cost SCMs, the industry has failed to overcometechnical hurdles that prevent full utilization of SCMs. A major problemis that SCMs are primarily industrial waste products that are notpurposely produced for blending with OPC. Although most SCMs arereactive to various extents, they are slower reacting then OPC.Partially replacing OPC with SCMs typically reduces strength bydilution, especially early strength. Increased SCM substitution furtherincreases strength loss by dilution.

There are essentially two commercial pathways for making blendedcement-intergrinding or simple blending. In simple blending, the OPC andSCM components are produced separately and blended together withoutintergrinding, either by dry blending or in the presence of water whenmaking fresh concrete. In intergrinding, cement clinker and one or moreSCMs are interground in a cement mill to a specified fineness to yieldthe finished blended cement. Self-blending of OPC and fly ash byconcrete manufactures is common in the United States while intergrindingto make finished blended cement is common in Europe, Latin America, andAsia.

SUMMARY

Disclosed herein are cement-SCM compositions having improved strength,particularly higher early strength, compared to cement-SCM compositionscomprised of, or made using, conventional blended cements. Alsodisclosed are components used to make cement-SCM compositions. Alsodisclosed herein are methods and systems for manufacturing cement-SCMcompositions and components thereof.

According to some embodiments, cement-SCM compositions are prepared byblending, without intergrinding, at least one finer particulatecomponent and at least one coarser particulate component (e.g., thecoarser particulate component having a D10, D50 and/or D90 that is aleast 1.5, 1.75, 2, 2.5, 3, 3.5, 4, or 5 times that of the finerparticulate component). Blending two or more particulate components,without intergrinding, provides greater control over the particle sizedistribution (PSD) of each particulate component or fraction and also ofthe resulting blended cement-SCM composition.

At least one of the finer or coarse particulate components ismanufactured by intergrinding two or more different types of materials.In some embodiments, the interground particulate component is a fineinterground particulate component that is thereafter blended, withoutintergrinding, with a coarse particulate component. In otherembodiments, the interground particulate component is a coarseinterground particulate component that is thereafter blended, withoutintergrinding, with a fine particulate component. In some cases, a fineinterground particulate component is blended, without intergrinding,with a course interground particulate component. Interground andnon-interground particulate components can be further modified byclassification in order to adjust the d90 and/or d10.

In some embodiments, a fine interground particulate component caninclude two or more different types of materials interground togetherthat can be blended with one or more coarser components. In someembodiments, a fine interground material can include one or morehydraulic cements interground with one or more SCMs. In someembodiments, a fine interground material can include one or moreclinkers or granules initially larger than about 1-3 mm interground withone or more finer materials smaller than about 1 mm. Intergrindingclinkers or granules with finer materials can be advantage when using amodern mill that requires some percentage of clinkers or granules to bepresent to form a stable grinding bed (e.g., vertical roller mills,horizontal roll presses, and the like). The clinkers or granules may behydraulic cement, granulated blast furnace slag, steel slag, othermetallurgical slags, pumice, limestone, aggregates, shale, tuff, trass,geologic materials, waste glass, glass shards, basalt, sinters,ceramics, recycled bricks, recycled concrete, ores, refractorymaterials, other waste industrial products, sand, and natural minerals.The finer SCM can be volcanic ash, shale dust, other natural pozzolan,or waste fines from aggregate processing.

In some embodiments, a cement-SCM composition comprises: (A) a fineinterground particulate component comprised of (1) a hydraulic cementfraction (e.g., Portland cement) and (2) a supplementary cementitiousmaterial (SCM) fraction; (B) a coarse particulate component comprised ofcoarse SCM particles not interground with the fine intergroundparticulate component; and optionally (C) an auxiliary particulatecomponent (e.g., OPC, SCM, or other material) not interground witheither of the fine interground particulate component or the coarseparticulate component.

In some embodiments, components for use in making cement-SCM compositioncan include: (A) a fine interground particulate component comprised of(1) a ground clinker or granule fraction formed from clinkers orgranules initially larger than 1-3 mm and (2) a ground finer fractionformed from particles or powders initially smaller than 1 mm; (B) acoarse particulate component comprised of coarse SCM particles notinterground with the fine interground particulate component; and (C) anSCM and/or hydraulically reactive particulate component not intergroundwith the fine interground particulate component or the coarseparticulate component.

In some embodiments, a cement-SCM composition comprises: (A) a fineinterground particulate component comprised of (1) a first SCM fractionand (2) a second SCM fraction; (B) a hydraulic cement component notinterground with the fine interground particulate component; and (C) acoarse particulate component comprised of coarse SCM particles notinterground with the fine interground particulate component or thehydraulic cement component; and optionally (D) an auxiliary particulatecomponent (e.g., OPC, SCM, or other material) not interground with anyof components (A), (B) or (C).

In some embodiments, a method of manufacturing a cement-SCM compositioncomprises: (A) intergrinding hydraulic cement (e.g., cement clinker)with one or more SCMs to form a fine interground particulate component;(B) blending, without intergrinding, the fine interground particulatecomponent with a coarse particulate component comprised of coarse SCMparticles; and optionally (C) further combining, without intergrinding,an auxiliary particulate component with the fine interground particulatecomponent and the coarse particulate component.

In some embodiments, a method of manufacturing a more reactive naturalpozzolan comprises intergrinding a granular material and/or limestonewith one or more natural pozzolans to form a fine intergroundparticulate component.

In some embodiments, a method of manufacturing a cement-SCM compositioncomprises: (A) intergrinding one or more clinkers or granules initiallylarger than about 1-3 mm with one or more finer particles or powdershaving an initial particle size less than about 1 mm to form a fineinterground particulate component; (B) blending, without intergrinding,the fine interground particulate component with a coarse particulatecomponent comprised of coarse SCM particles; and optionally (C) furthercombining, without intergrinding, an auxiliary particulate componentwith the fine interground particulate component and the coarseparticulate component. Where fine interground component (A) isinsufficiently hydraulically reactive, the auxiliary particulatecomponent may advantageously include hydraulically reactive particles(e.g., Portland cement).

In some embodiments, a method of manufacturing a cement-SCM compositioncomprises: (A) intergrinding (1) a first SCM component and (2) a secondSCM component to form a fine interground particulate component; (B)blending, without intergrinding, the fine interground particulatecomponent with a hydraulic cement component; and (C) blending, withoutintergrinding, the fine interground particulate component and thehydraulic cement component with a coarse particulate component; andoptionally (D) further combining, without intergrinding, an auxiliaryparticulate component (e.g., OPC, SCM, or other material) withcomponents (A), (B) and (C).

In some embodiments, a system of manufacturing a cement-SCM compositioncomprises: (A) one more milling apparatus configured to intergrindhydraulic cement (e.g., cement clinker) and one or more SCMs to form afine interground particulate component; (B) one or more blendingapparatus configured to blend, without intergrinding, the fineinterground particulate component with a coarse particulate componentcomprised of coarse SCM particles; and optionally (C) one or moreapparatus for combining, without intergrinding, an auxiliary particulatecomponent with the fine interground particulate component and the coarseparticulate component.

In some embodiments, a system of manufacturing a cement-SCM compositioncomprises: (A) one more milling apparatus configured to intergrind oneor more clinkers or granules initially larger than about 1-3 mm with oneor more finer particles or powders having an initial particle size lessthan about 1 mm to form a fine interground particulate component; (B)one or more blending apparatus configured to blend, withoutintergrinding, the fine interground particulate component with a coarseparticulate component comprised of coarse SCM particles; and optionally(C) one or more apparatus for combining, without intergrinding, anauxiliary particulate component with the fine interground particulatecomponent and the coarse particulate component. Where fine intergroundcomponent (A) is insufficiently hydraulically reactive, the auxiliaryparticulate component may advantageously include hydraulically reactiveparticles.

In some embodiments, a system of manufacturing a cement-SCM compositioncomprises: (A) one more milling apparatus configured to intergrind (1) afirst SCM component and (2) a second SCM component to form a fineinterground particulate component; (B) one or more blending apparatusconfigured to blend, without intergrinding, the fine intergroundparticulate component with a hydraulic cement component; and (C) one ormore blending apparatus configured to blend, without intergrinding, thefine interground particulate component and the hydraulic cementcomponent with a coarse particulate component; and optionally (D) one ormore apparatus for combining, without intergrinding, an auxiliaryparticulate component (e.g., OPC, SCM, or other material) withcomponents (A), (B) and (C).

In some embodiments, the coarse particulate component can be made bygrinding one or more SCMs to a relatively high D90, and/or classifying(e.g., dedusting to remove overly fine particles to achieve a desiredD10), and/or classifying or sieving to remove overly coarse particles.

In some embodiments, the auxiliary particulate component can include oneor more cements and SCMs, as described herein, OPC, magnesium cement,aluminate cement, bottom ash, fly ash, GGBFS, steel slag, limestone,etc.

Activated natural pozzolan compositions may comprise an intergroundblend of natural pozzolan (e.g., volcanic ash or other naturalpozzolanic deposit that is initially unactivated and contains moisture,e.g., at least 3% moisture) and at least one initially granular orcoarse material that is not cement clinker, wherein intergrinding theinitially unactivated natural pozzolan with the initially granular orcoarse material activates the natural pozzolan by reducing its particlesize and reducing its moisture content (e.g., to less than 0.5%). Theresult is a fine interground blended SCM material in which the naturalpozzolan has been activated.

In some embodiments, a method of activating a natural pozzolan comprisesintergrinding a granular SCM material (e.g., having an initial particlesize greater than 2 mm) with a natural pozzolan material having amoisture content of at least 3% to form an interground particulate SCMmaterial having a moisture content of less than 0.5%. The method mayinclude intergrinding a granulated or coarse material and a fine,initially unactivated, pozzolan in a vertical roller mill (VRM),horizontal roll press, or any mill that requires coarse particles(granules) at least 2 mm in size to form a stable bed. The naturalpozzolan to be activated can be volcanic ash or other natural pozzolanicdeposit. The coarse or granular SCM that is interground with the naturalpozzolan to activate it can be one or more of blast furnace slag, steelslag, other metallurgical slags, glass shards, limestone, basalt,pumice, geological materials, fine aggregates, ground shale, tuff,trass, and waste concrete. The activated pozzolan composition preferablycontains little or no Portland cement (i.e., <30%, <25%, <20%, <15%,<10%, <5%, <1%, or essentially none).

These and other advantages and features of the invention will becomemore fully apparent from the following description and appended claims,or may be learned by the practice of the invention as set forthhereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

To further clarify the above and other advantages and features of thepresent invention, a more particular description of the invention willbe rendered by reference to specific embodiments thereof which areillustrated in the appended drawings. It is appreciated that thesedrawings depict only illustrated embodiments of the invention and aretherefore not to be considered limiting of its scope. The invention willbe described and explained with additional specificity and detailthrough the use of the accompanying drawings in which.

FIGS. 1A and 1B are illustrative particle size distribution (PSD) chartsof exemplary ordinary Portland cement (OPC) subdivided to show fine,medium, and coarse fractions;

FIG. 2A is PSD chart of a finely ground cement clinker subdivided toshow fine, medium, and coarse fractions;

FIG. 2B is a PSD chart comparing the PSD of the finely ground cementclinker of FIG. 2A with the PSD of a finely interground cement clinkerand natural pozzolan having an approximate bimodal PSD, with estimatedproportioning of the cement and pozzolan fractions within the fine,medium, and coarse fractions;

FIG. 3A is a PSD chart of another finely ground cement material madeusing cement clinker and subdivided to show fine, medium, and coarsefractions;

FIG. 3B is a PSD chart comparing the PSD of the finely ground cementmaterial of FIG. 3A with the PSD of another finely interground cementclinker and natural pozzolan having an approximate bimodal PSD, withestimated proportioning of the cement and pozzolan fractions within thefine, medium, and coarse fractions;

FIG. 3C is a PSD chart of a fine interground cement clinker and naturalpozzolan, with estimated proportioning of the cement and pozzolanfractions within the fine, medium, and coarse fractions;

FIG. 4A is graph illustrating the PSD of another finely intergroundcement clinker and natural pozzolan without an apparent bimodal PSD,with estimated proportioning of the cement and pozzolan fractions withinthe fine, medium, and coarse fractions;

FIG. 4B is graph illustrating the PSD of an interground limestone andnatural pozzolan having an approximate bimodal PSD, with estimatedproportioning of the limestone and pozzolan fractions within the fine,medium, and coarse fractions;

FIG. 5A is a photograph made using a conventional microscope of sievednatural pozzolan particles that are opaque and have a more roundedmorphology;

FIG. 5B is a photograph made using a conventional microscope of sievednatural pozzolan particles that have a glassy appearance and a jaggedand flat morphology;

FIGS. 6-9 are flow diagrams illustrating example methods ofmanufacturing Cement-SCM compositions and/or components thereof;

FIGS. 10A and 10B schematically illustrate example milling apparatus formanufacturing one or more components of a cement-SCM composition,including a fine interground particulate component;

FIG. 11 is a flow diagram illustrating an example method ofmanufacturing a coarse supplementary cementitious material (SCM),including at least a portion of a coarse particulate component;

FIG. 12 schematically illustrates an example separation apparatus foruse in making one or more components of a cement-SCM composition,including a coarse SCM; and

FIGS. 13A-13C schematically illustrate exemplary manufacturing systemsfor making one or more cement-SCM compositions.

DETAILED DESCRIPTION I. Introduction

Disclosed herein are cement-SCM compositions having improved strength,particularly higher early strength, compared to cement-SCM compositionscomprised of, or made using, conventional blended cements. Alsodisclosed herein are methods and systems for manufacturing cement-SCMcompositions.

According to some embodiments, cement-SCM compositions include a fineinterground particulate component made by intergrinding one or moreclinkers (e.g., Portland cement clinker) and one or more supplementarycementitious materials (SCMs) and a coarse particulate componentcomprised of coarse SCM particles that are not interground with the fineinterground particulate component. The cement-SCM composition mayoptionally include an auxiliary particulate component that is notinterground with the fine interground particulate component or thecoarse particulate component.

Intergrinding hydraulic cement and SCM yields a fine intergroundparticulate component having a high level of reactivity, both withrespect to the hydraulic cement fraction and also the SCM fraction. Thefine interground particulate component can typically have a narrowparticle size distribution (PSD) and/or a d90 that is significantlylower than the d90 of ordinary Portland cement (OPC). The fineinterground particulate component contributes substantially to strengthdevelopment, including high early strength and also late strength. Thecoarse particulate component typically includes SCM particles that areless expensive, less reactive, and have lower energy and carbonfootprints compared to hydraulic cement particles, which mainly providea filling effect, particularly in the early stages of strengthdevelopment.

Blending, without intergrinding, the fine interground particulatecomponent with the coarse particulate component composed of SCMparticles yields a cement-SCM composition that combines the beneficialhigh early strength effect of the fine interground particulate componentwith the beneficial PSD-broadening effect of the coarse particulatecomponent. The cement-SCM composition has a broadened overall PSDcompared to the PSD of the fine interground particulate component byitself, which offsets the otherwise suboptimal PSD of the fineinterground particulate component. The overall PSD of the cement-SCMcomposition can advantageously be optimized to be as broad or broaderthan the PSD of OPC. Broadening the PSD can reduce viscosity, yieldstress, water demand, and shrinkage of the cement paste, increase cementpaste density, and improve long-term durability of concrete madetherewith.

In addition, blending, without intergrinding, a fine intergroundparticulate component with a coarse particulate component yields acement-SCM composition in which the particle packing density (PPD) ofthe overall cement-SCM composition is higher than the PPD of either thefine interground particulate component or the coarse particulatecomponent by themselves prior to blending. The overall PPD of thecement-SCM composition can advantageously be optimized to be as high orhigher than the PPD of OPC. Increasing the PPD can reduce water demandand shrinkage of the cement paste, increase paste density, and improvelong-term durability of concrete. Moreover, because standard intergroundblended cements are often ground more finely than OPC (e.g., by about10-20%) to increase reactivity and offset strength loss resulting fromreduced cement clinker content, they typically have a d90 and/or a PPDthat is lower than the d90 or PPD of OPC. A lower d90 and/or PPD ischaracterized by higher water demand and shrinkage. In contrast, becausethe cement-SCM compositions disclosed herein can have a d90 and/or PPDthat is optimized to be significantly higher than the d90 or PPD ofconventional interground blended cements, they can have lower waterdemand and shrinkage, higher paste density, and greater long-termdurability compared to conventional interground blended cements.

Similar intergrinding processes can be used to manufacture a blended SCMmaterial, such as an initially coarse granular SCM 1-3 mm in size withan initially fine SCM powder that might otherwise be difficult to grindin a VRM or horizontal roll press. To form a stable bed, the initiallycoarse granular SCM is used to form a stable bed and interground withthe finer SCM. For example, a volcanic ash or natural pozzolan having amoisture content or which is otherwise insufficiently reactive can beinterground with a granular material to form an activated pozzolan orSCM blend having reduced moisture and finer particle size. The coarsegranular SCM can be granulated blast furnace slag, steel slag, othermetallurgical slags, pumice, limestone, dolomite, aggregates, sand,quartz, glass shards, recycled bricks or ceramics, recycled concrete,basalt, ores, shale, tuff, trass, or other geologic material.

If the mill used to intergrind cement clinker and initially moist SCMgenerates sufficient heat, such as a ball mill or VRM, the heat may besufficient to prevent moisture released from the initially moist SCMfrom reacting with and prematurely hydrating a portion of ground cementclinker. Alternatively, grinding aids, such as alkyl amines or alcoholamines, can form a coating that protects or shield cement particles fromprematurely hydrating. In some cases, it may be desirable or necessaryto at least partially pre-dry the initially moist SCM to preventpremature hydration of ground cement particles. On the other hand,activating natural pozzolans that initially contain excessive moistureby intergrinding with coarse granular SCM materials instead of cementclinker prevents excessive moisture released from the natural pozzolanfrom undesirably and prematurely reacting with cement clinker, which canreduce cement reactivity and ultimate strength.

A. Review of Conventional Cements and Blended Cements

As used herein, the term “ordinary Portland cement” (“OPC”) refers toType I, II and V cements, according to ASTM C-150, and other cementshaving similar PSDs. By way of example, FIG. 1A is a PSD chart showingdata measured by a laser diffraction technique of a commerciallyavailable Type I/II OPC having a Blaine fineness of 376 m²/kg (asreported by its manufacturer). The PSD chart is further subdivided intothree regions or fractions designated as “fine” (e.g., <5 μm), “medium”(e.g., 5-30 μm), and “coarse” (e.g., >30 μm). It will be appreciatedthat these particle size ranges and cutoffs are for illustration andcomparison purposes and should not be taken as absolute or necessarilydefinitional. Other numeric ranges and cutoffs can be used to designatefine, medium, and coarse fractions of cement or cement-SCM blends. Forexample, the cutoff between the “fine” and “medium” fractions can be anyinteger or decimal number between 3-15 μm. Similarly, the cutoff betweenthe “medium” and “coarse” fractions can be any integer or decimal numberbetween 10-40 μm. For example, if the cutoff between fine and mediumfractions were set at 8 μm and the cutoff between the medium and coarsefractions were set at 24 μm, particles below 8 μm would be “fine”,particles between 8-24 μm would be “medium”, and particles above 24 μmwould be “coarse”.

FIG. 1B is a PSD chart showing data measured by a Malvern Mastersizer2000 of a ground cement clinker material milled using a vertical rollmill (VRM) to a d90 within a typical range of about 40-45 μm. The rawunground clinker was obtained from Drake Cement, Paulen, Arizona, andthe VRM was manufactured by Gebr. Pfeiffer, located in Kaiserslautern,Germany. The PSD of the ground cement clinker shown in FIG. 1B issteeper than the PSD of the OPC shown in FIG. 1A, with a d90 of about43.4 μm, a d50 of about 18.8 μm, and a d10 of about 3.8 μm). The groundcement clinker in FIG. 1B has fewer “fine” particles than the OPC ofFIG. 1A, as illustrated by the smaller cross-hatched area designed as“fine”. Nevertheless, both Portland cement materials have a typical d90(e.g., about 40-45 μm) and also a typical d50 (e.g., about 18-20 μm) andtherefore contain a substantial proportion of coarse cement particlesthat may not fully hydrate, particularly at lower water-to-cement ratios(w/c). Steeper PSDs are typical of OPC made using a VRM and othermodern, more efficient grinding apparatus such as a horizontal rollpress. Older, less efficient grinding apparatus such as a ball millproduce broader PSD cement. OPC made using modern mills having a PSD andconsidered too narrow is sometimes further processed using a ball millto produce a higher proportion of fine cement particles and therebyflatten the PSD curve.

Even though the PSD of conventional OPC can be measured and representedby a PSD chart, OPC is rarely, if ever, marketed and sold based on PSD.Instead, cement producers almost universally describe cement in terms ofits “fineness” or specific surface area as a description of itsreactivity. The “Blaine fineness” (or simply “Blaine”) is a singlenumeric value that can be estimated (not directly measured) using an airpermeability test and has units of either cm²/g or m²/kg, which differby a factor of 10. Thus, a “Blaine” of 4000 cm²/g means the same thingas a Blaine of 400 m²/kg. The simplicity of the Blaine standard beliesits inherent weakness, which is the inability to account for differencescaused by varying PSD. For example, two different cements can have theexact same Blaine number yet vary greatly in how they behave because ofdifferences in PSD. For example, the PSD curves in FIGS. 1A and 1B havevery different proportions of cement particle sizes along the curve andwill behave differently when used to make concrete even if their Blainenumbers were identical. And even if the cements shown in FIGS. 1A and 1Bhave different Blames, either curve could be shifted to the left or theright in order to make the Blames identical. But doing so would not makethe cements behave the same because the shapes of the PSD curves wouldstill differ substantially.

Conventional blended cements formed by either intergrinding or simplemixing without intergrinding can be suboptimal in several ways. It iswell-known, for example, that OPC, particularly Type I, II or V cement,includes a substantial quantity of coarse cement particles that are toolarge to completely hydrate, even after several months or years,particularly in high performance concrete having a w c less than 0.42.As a result, concrete made therefrom may contain a substantial quantityof “wasted cement” that acts as an expensive filler and representsunused potential reactivity and strength-producing ability. The wastedcement also represents and is proportional to “wasted energy” consumedand “wasted carbon dioxide” emitted during the manufacture of cementclinker. If the d90 of a standard blended cement is similar to that ofOPC, the blended cement will, like OPC, contain a substantial quantityof coarse cement particles that are too large to completely hydrate andare therefore “wasted cement”. Moreover, even though replacing a portionof the cement with SCM in blended cements reduces the number of coarsecement particles, it also reduces the number of highly reactive finecement particles, which can have a negative effect on strengthdevelopment, particularly early (e.g., 1-7 day) strength.

Alternatively, if the blended cement has a d90 that is lower than thed90 of OPC (i.e., in order to increase reactivity), the blended cementwill typically have higher water demand and shrinkage and can have lowerpaste density and reduced long-term durability compared to OPC. If theblended cement were hypothetically ground, such as by intergrinding, toa very high fineness and/or low d90 in order to substantially orentirely eliminate wasted cement and create high reactivity, suchhypothetical blended cement would likely form cement paste having veryhigh water demand and shrinkage and yield concrete having low long-termdurability.

Blended cements made by intergrinding cement clinker and one or moreSCMs to make the finished blended cement product are often ground usingthe same milling apparatus as OPC and can have the same Blaine finenessas OPC. However, because of reduced strength caused by intergrindingcement with less reactive SCMs, producers often compensate by grindingblended cement more finely to raise the Blaine number (e.g., from 380m²/kg to 420 m²/kg for OPC to 420 m²/kg to 550 m²/kg for intergroundblends). Even so, cement producers must strike a balance betweengrinding more finely to increase reactivity, on the one hand, andavoiding grinding too finely to avoid excessive water demand andshrinkage, on the other. Thus, grinding more finely to improve strengthprovides only a small window of opportunity that is limited by thecompeting and offsetting effects of increased fineness.

The foregoing examples illustrate the impossibility, using conventionalmethods of intergrinding or simple blending, of manufacturing blendedcements that simultaneously have (1) high reactivity as a result ofincluding fine cement and SCM fractions and eliminating coarse cementparticles and (2) adequately low water demand, low shrinkage, high pastedensity, and high concrete durability as a result of including asufficient quantity of coarse particles that cause the blended cement tohave a broad PSD (e.g., a Fuller distribution) made of both fine andcoarse particles.

In contrast to conventional methods for making blended cements, theinventive compositions, methods and systems disclosed herein permit themanufacture of improved cement-SCM compositions, including dry blendedcements and/or fine and coarse components that can be combined intoblended cement at the time of making concrete, which combine thebeneficial effects of finely ground cement and SCM materials, whichsignificantly increases strength, particularly early strength, with thebeneficial effects of including coarse particles, which significantlybroadens the PSD, increases the PPD, reduces water demand and shrinkage,increases paste density, and yields concrete having higher long-termdurability.

B. Analytical Framework and Methodology for Analyzing Existing BlendedCements and Designing and Manufacturing Blended Cements and OtherCement-SCM Compositions

Apart from the inventive cement-SCM compositions, methods, and systemsdisclosed herein, a new and useful analytical framework and methodologyis proposed for analyzing known cements and blended cements, as well asproposed blended cements and other cement-SCM compositions, for thepurpose of predicting permissible SCM replacement levels for a given setof hydraulic cement and SCM inputs. The proposed analytical frameworkand methodology includes: (1) three fundamental principles for designingand producing well-optimized blended cements; (2) a process foranalyzing different blended cements to determine how well they complywith the three fundamental principles to produce an optimization score;and (3) a process for predicting permissible SCM replacement levelsbased on the optimization score.

A “permissible” SCM replacement level for a blended cement or othercement-SCM composition means the composition will advantageously andreliably provide adequate strength, acceptable water demand, and otherperformance criteria based on predetermined standards. According to someembodiments, one proposed standard is whether a blended cement reliablyproduces strength, including early and late compressive strengths, thatequal or exceed the compressive strength of OPC and has a water demandsimilar to that of OPC.

The new analytical framework was derived from empirical data showing howblended cements compared to appropriate control cements relative toearly strength (1-7 day), late strength (7-182 day), and water demand.

The “three fundamental principles” proposed herein are:

-   -   1. minimize the quantity of “coarse” hydraulic cement particles        (e.g., >30 μm);    -   2. minimize the quantity of overly fine hydraulic cement        particles (<5 μm);    -   3. maintain a broad particle size distribution (PSD).

“Coarse” hydraulic cement particles that do not fully hydrate within aspecified time duration (e.g., 91 days) essentially become “wastedcement”. An excessive quantity of “fine” hydraulic cement particles as aproportion of overall particles in the cement-SCM composition increaseswater demand as a result of excessive surface area and flocculationwithout providing a corresponding strength benefit. A broad particlesize distribution increases particle packing density, reduces waterdemand, shrinkage, and ion permeability, and increases workability,paste density, strength, and long-term durability.

Based on an analysis of empirical data, it has been determined and isproposed that the three fundamental principles may not have equal effecton their analytical and predictive ability. By way of example and notlimitation, they can be weighted as follows relative to their observedpredictive effect on optimization:

-   -   Principle 1 (minimize oversized cement particles)—1.5 (maximum        score);    -   Principle 2 (minimize undersized cement particles)—1.0 (maximum        score);    -   Principle 3 (maintain broad PSD)—1.5 (maximum score).

By way of example, cements and blends in compliance with a givenprinciple can be awarded the maximum score for that principle.Conversely, cements and cement blends in violation of a given principlecan be awarded a minimum score of “zero” for that principle. Cements andcement blends in partial compliance with a given principle can beawarded a partial score between zero and the maximum score depending onthe degree of compliance or violation. The “optimization score” for acement or blended cement (actual or proposed) is the sum of all threescores. Increasing scores indicate the ability to substitute more SCMsfor ordinary Portland cement. A “perfect score” under the currentlyproposed scoring system is 4.0. The optimization score is easy todetermine and, unlike the Blaine standard or even a detailed PSD chart,the optimization score has been found to be quite accurate in itsability to analyze and predict permissible SCM substitution levels.

In addition, the optimization score appears to be largely independent ofthe type of SCM that is utilized and is therefore very robust as apredictive tool regardless of the SCM used to make blended cement. Forexample, blended cements in substantial compliance with all threefundamental principles reportedly produced similar compressive andflexural strengths when using various combinations of SCMs selected fromground granulated blast furnace slag (GGBFS), Class F fly ash, steelslag, and limestone, even at very high substitution levels (55-75%).This is particularly surprising since GGBFS, Class F fly ash, steelslag, and limestone have very different chemistries and reactivities.

It is further proposed that a permissible SCM replacement level for awide variety of different blended cements can be quickly and accuratelyestimated by comparing its optimization score with optimization scoresdetermined using the proposed analytical system for blended cementsdescribed in the Examples below. The blended cements shown in theExamples had SCM replacement levels of 20%, 35%, 55%, and 75%,respectively. Coupled with a proposed baseline optimization score for100% OPC, the proposed analytical framework provides a comparative toolthat involves well-spaced SCM substitution levels ranging from 0-75%.Using the proposed analytical framework and methodology, one can analyzethe strengths and weaknesses of existing and proposed blended cementsand other cement-SCM compositions and then efficiently manufactureblended cements and other cement-SCM compositions that more effectivelyutilize SCMs as a partial replacement for hydraulic cement, such asPortland cement.

II. Cement-SCM Compositions

In some embodiments, a cement-SCM composition comprises: (A) a fineinterground particulate component comprised of (1) a hydraulic cementfraction and (2) a supplementary cementitious material (SCM) fraction;(B) a coarse particulate component comprised of coarse SCM particles notinterground with the fine interground particulate component; andoptionally (C) an auxiliary particulate component (e.g., OPC, SCM, orother material) not interground with either of the fine intergroundparticulate component or the coarse particulate component.

In some embodiments, components for use in making cement-SCM compositioncan include: (A) a fine interground particulate component comprised of(1) a ground clinker or granule fraction formed from clinkers orgranules initially larger than 1-3 mm and (2) a ground finer fractionformed from particles or powders initially smaller than 1 mm; (B) acoarse particulate component comprised of coarse SCM particles notinterground with the fine interground particulate component; and (C) anSCM and/or hydraulically reactive particulate component not intergroundwith the fine interground particulate component or the coarseparticulate component.

In some embodiments, a cement-SCM composition comprises: (A) a fineinterground particulate component comprised of (1) a first SCM fractionand (2) a second SCM fraction; (B) a hydraulic cement component notinterground with the fine interground particulate component; and (C) acoarse particulate component comprised of coarse SCM particles notinterground with the fine interground particulate component or thehydraulic cement component; and optionally (D) an auxiliary particulatecomponent (e.g., OPC, SCM, or other material) not interground with anyof components (A), (B) or (C).

Cement-SCM compositions disclosed herein can be made using hydrauliccement and SCM materials known in the art of cement and concretemanufacture. Examples of cement fractions, SCM fractions, binary,ternary and quaternary cement-SCM blends and compositions that can bemade according to the methods and systems disclosed herein are found inU.S. Pat. Nos. 7,799,128, 7,972,432, 8,323,399, 8,974,593, 9,067,824,8,414,700, 8,377,201, 8,551,245 and 9,102,567, the disclosures of whichare incorporated herein in their entirety.

The terms “hydraulic cement” and “cement”, as used herein, includePortland cement and similar materials that contain one or more of thefour clinker materials: C₃S (tricalcium silicate), C₂S (dicalciumsilicate), C₃A (tricalcium aluminate), and C₄AF (tetracalciumaluminoferrite). Hydraulic cement can also include ground granulatedblast-furnace slag (GGBFS) and other slags having a relatively high CaOcontent (which may also qualify as SCMs), white cement, calciumaluminate cement, high-alumina cement, magnesium silicate cement,magnesium oxychloride cement, oil well cements (e.g., Type VI, VII andVIII), and combinations of these and other similar materials.

In some embodiments, the hydraulic cement fraction of a fine intergroundparticulate component and/or the overall cement-SCM composition can havea C₃S content of at least 55%, 57%, 60%, 65%, 70%, or 75% by weightand/or a C₃A content of at least 5%, 6%, 7%, 8%, 10%, 12%, or 15% byweight and/or a total tricalcium mineral content (C₃S+C₃A) of at least63%, 65%, 68%, 72%, 77%, 82%, or 87%.

The terms “supplementary cementitious material” and “SCM” shall includeany material commonly understood in the industry to constitute materialsthat can replace a portion of hydraulic cement in concrete, either inblended cements or added by end users when making concrete or othercementitious materials. The terms “Supplementary cementitious material”and “SCM”, as used herein, shall also broadly encompass any materialthat can be or has been processed in such a way as to capable ofreplacing a portion of Portland or other hydraulic cement in concrete.Non-limiting examples of SCMs include highly reactive materials (e.g.,GGBFS), moderately reactive materials (e.g., Class C fly ash, steelslag, silica fume, and metakaolin), lower reactive materials (e.g.,Class F fly ash, calcined clays, natural pozzolans, ground pumice,ground glass, and metastable forms of CaCO₃), and filler materials(e.g., ground limestone, clay, ground shale, ground quartz, groundgeologic materials, ground recycled concrete, washout fines fromconcrete trucks, mine tailings, and precipitated CaCO₃). There areclaims that some unreactive filler materials, such as ground limestone,ground quartz, and precipitated CaCO₃, can become or be made to bereactive under certain circumstances.

In some embodiments, a fine interground particulate component caninclude two or more different types of materials interground togetherthat can be blended with one or more coarser components. In someembodiments, a fine interground material can include one or morehydraulic cement clinkers interground with one or more SCMs. In otherembodiments, a fine interground material can include one or more typesof clinkers or granules initially larger than about 1-3 mm (e.g.,cement, metallurgical slags, limestone, pumice, coal ash, sinters, wasteglass, calcined shale, natural pozzolans, bricks, ceramics, recycledconcrete, refractory materials, other waste industrial products,aggregates, sand, natural minerals interground with one or more finerSCMs having an initial particle size <1 mm (e.g., volcanic ash, naturalpozzolans, shale dust, fly ash, waste fines from aggregate processing,red mud).

In some embodiments, at least one of the SCM fraction of the fineinterground particulate component or the coarse SCM particles of thecoarse particulate component may comprise one or more SCM materialsselected from coal ashes, slags, natural pozzolans, ground glass, andnon-pozzolanic materials. By way of example, coal ashes can be selectedfrom fly ash and bottom ash, slags can be selected from groundgranulated blast furnace slag, steel slag, and metallurgical slagcontaining amorphous silica, natural pozzolans can be selected fromnatural pozzolanic deposits, volcanic ash, metakaolin, shale dust,calcined clay, trass, and pumice, ground glass can be selected frompost-consumer glass and industrial waste glass, and non-pozzolanicmaterials can be selected from limestone, metastable calcium carbonateproduced by reacting CO₂ from an industrial source and calcium ions,precipitated calcium carbonate, crystalline minerals, clay, ores, minetailings, ground shale, hydrated cements, and waste concrete (includingground recycled concrete and washout fines).

The cement-SCM compositions disclosed herein may contain components,such as the fine interground particulate component and/or the coarseparticulate component, which are not generally used in the cementindustry to make general purpose cements. For example, the fineinterground particulate component may, by itself, be considered to betoo fine for use as general purpose cement to make concrete. In someembodiments, the coarse particulate component may be considered to betoo coarse and unreactive for use as a partial cement substitute whenmaking blended cement and concrete. However, when blended together, thefine interground and coarse particulate components synergisticallyinteract to create a blended cement or other cement-SCM compositionhaving properties that are not only adequate for use as general purposecement but which can be superior to general purpose cements currentlyused in the cement and concrete industries. In some embodiments,particularly where simplicity of manufacture is desired rather thanmaximizing SCM substitution level, the fine interground particulatecomponent may be combined with a commercially available SCM, such as flyash, GGBFS, raw feed for cement kilns, mine tailings, washout fines, orshale dust without modification.

As discussed above, a trend in the cement industry is to grind cements,particularly blended cements, more finely to increase reactivity andearly strength-building potential. Over the past few decades, the Blainefineness of cements and blended cements has increased. The benefit isincreased reactivity. However, one detriment is decreased durabilityresulting from the decreased particle size, particularly the lowering ofthe d90, which reduces the preponderance of coarse particles in thecement paste. All things being equal, increased fineness increasesshrinkage. Moreover, and especially in the absence of high pozzolanusage, finer cements can yield concrete having increased porosity andion permeability, which increase the likelihood of chemical attack andreduced long-term durability.

Nevertheless, even modern finely ground cements, including intergroundblended cements, contain substantial quantities of coarse cementparticles that never fully hydrate, even after months or years. In fact,the cement industry has reached a practical limit as to how finely itcan grind OPC and blended cement (i.e., because making cement even finerwill further exacerbate problems associated with shrinkage, waterdemand, cement paste density, and long-term durability). Moreover,partial replacement of cement with SCMs generally reduces strength,particularly early strength, of concrete, although well-designed andwell-tended concrete having high SCM content may, over time, gain asmuch or more strength as concrete made using a similar quantity of 100%OPC. Because the industry solution to low SCM reactivity is to grindSCMs more finely, but because fineness limits have essentially beenreached, there is a practical barrier that prevents the cement industryfrom grinding cements and blended cements even more finely. As a result,blended cements remain suboptimal and SCM substitution levels remainlow.

For example, the Devils Slide plant of Lafarge-Holcim, located in DevilsSlide, Utah, produces an interground blend of 75% Portland cement and25% pozzolan (e.g., natural pozzolan) called “1P (25) Natural Pozzolan”that meets the requirements of ASTM C595 for Type 1P cement. To offsetthe early strength reducing effect of replacing 25% of the Portlandcement with natural pozzolan, the Blain fineness is increaseddramatically to 533 m³/kg (Spec Sheet Version 180412). Although 25%substitution is relatively high for interground blends, it is not nearlyas high as it could be if the interground blend were blended, withoutintergrinding, with a coarse SCM material according to the principlesdisclosed herein.

For example, 1P (25) Natural Pozzolan can be blended, withoutintergrinding, with a coarser SCM, such as waste shale dust produced asa byproduct by Utelite during manufacture of calcined shale lightweightaggregate, which is located just a few miles from the Devils Slide plantin Coleville, Utah. The Utelite shale dust has a PSD, as measured usinga Microtrac—X100 particle size analyzer by RSG Inc. of Silicaga, A L, inwhich the d90 is 112.6 μm, the d50 is 24.22 μm, and the d10 is 3.526 μm.This material was tested and has pozzolanic properties comparable to flyash. Blending shale dust with 1P (25) Natural Pozzolan yields aparticulate blend having a substantially broader PSD than 1P (25)Natural Pozzolan by itself, which greatly increases particle packingdensity, decreases shrinkage, and improves long-term durability. Forexample, blending two parts 1P (25) Natural Pozzolan with one part shaledust yields a cement-SCM blend containing 50% Portland cement and 50%pozzolan. Not only is this blend superior to 1P (25) Natural Pozzolan byitself, it qualifies as “high volume” pozzolan cement since it has 50%replacement.

Another cement-SCM blend that can easily be made using 1P (25) NaturalPozzolan as the fine interground particulate material is to simplyblend, without intergrinding, the 1P (25) Natural Pozzolan with aportion of the raw feed for the cement kiln made by the Devils Slideplant, which would provide an essentially inexhaustible supply of coarseSCM. A typical raw feed contains up to about 90% ground limestone andapproximately 10% clay or ground shale and a minor amount of an ironsource, such as ground iron ore. Because limestone, clay, ground shale,and ground iron ore are described elsewhere herein as suitablenon-reactive SCM fillers, the raw feed is an excellent coarse SCMblending material. Because the raw feed is made using a vertical rollermill, the PSD can be controlled to provide a coarse SCM and cement-SCMblend with controlled PSD, particle packing density, water demand, andreactivity, among other things.

Yet another cement-SCM blend that can be easily made using 1P (25)Natural Pozzolan as the fine interground particulate material is toblend, without intergrinding, the 1P (25) Natural Pozzolan with minetailings. For example, there is an enormous mountain of mine tailingsfrom the Bingham copper mine on the south side of Interstate-80 nearSalt Lake City, Utah. These mine tailings contain mainly waste orematerials and are generally inert. They can be used as is and/orclassified and/or ground to produce a coarse SCM that is blended with afine interground particulate component, such as 1P (25) NaturalPozzolan. Even if the Bingham mine tailings contain some quantity ofheavy metals, it is known that once encapsulated in cement paste, suchmaterials do not leach from concrete. Using mine tailings as a partialreplacement of Portland cement yields multiple benefits: an inexpensiveand essentially inexhaustible supply of coarse SCM; cement-SCM blendswith broader PSD and higher particle packing density; and a way to cleanup and put the mine tailings to beneficial use.

Even still, another cement-SCM blend that can be easily made using 1P(25) Natural Pozzolan as the fine interground particulate material is toblend, without intergrinding, the 1P (25) Natural Pozzolan with wasteconcrete (ground recycled concrete or washout fines). For example, everyconcrete plant creates washout fines on a daily basis while cleaningconcrete trucks following deliveries. These washout fines are recoveredfrom a washout pond and typically stored in a pile for drying and use asinexpensive road base or other fill applications. The washout finestypically have high alkalinity and may have some amount of unhydratedcement values. The high alkalinity of washout fines can help activatethe natural pozzolan in the 1P (25) Natural Pozzolan, and the pozzolancan bind to and neutralize alkali metals from the washout fines. Usingwashout fines and ground recycled concrete as a partial replacement ofPortland cement yields multiple benefits: an inexpensive and steadysupply of coarse SCM; cement-SCM blends with broader PSD and higherparticle packing density; and a way to clean up and put the washoutfines and/or ground recycled concrete to beneficial use.

Because blending the 1P (25) Natural Pozzolan with a coarse SCM broadensthe particle size distribution, it is possible to grind the 1P (25)Natural Pozzolan even more finely to increase the reactivity of thecement and natural pozzolan without creating an unduly fine cementitiousmaterial. The increased fineness will offset any early strengthreduction that may be caused by blending with the raw feed, which isessentially unreactive but nonetheless contributes to overall strengthand durability through the filler effect and by providing nucleationsites (e.g., by the limestone, clay and/or shale particles).

The cement-SCM compositions disclosed herein provide a simple andelegant, yet powerful and heretofore overlooked, solution to problemsfaced by the cement industry. The fine interground particulate componentincludes a highly reactive hydraulic cement fraction that provides highearly strength and/or is sufficiently fine and/or devoid of coarsecement particles that do not fully hydrate so that the hydraulic cementfraction is able to substantially fully hydrate in a standard definedtime period (e.g., within 6 months, 3 months, 56 days, or 28 days). Thefine interground particulate component also provides a highly reactiveSCM fraction, such as highly reactive pozzolan particles and/orlimestone or other filler particles that provide nucleation sites thatpromote hydration of the hydraulic cement fraction. The fine SCMparticles may also reduce water demand by being essentiallynon-dissolving, non-flocculating, and less absorptive of water comparedto fine cement particles in the early stages after mixing with water toform freshly mixed concrete, when workability is more important thanstrength development. In addition, the fine SCM particles can helpdisperse the fine cement particles and reduce their flocculation, whichfurther lowers water demand and contributes to workability. In short,the fine interground particulate component provides hydraulic cement andSCM fractions having very high reactivity and high early strengthpotential but without creating unnecessarily high water demand, whichcan occur if the cement-SCM composition contains only fine hydrauliccement particles and is substantially or entirely devoid of fine SCMparticles.

Another advantage of the fine interground particulate component is thatit greatly simplifies the ability and/or reduces the cost of providingboth fine hydraulic cement particles and fine SCM particles. Forexample, the authors of Zhang, et al., “A new gap-graded particle sizedistribution and resulting consequences on properties of blendedcement,” Cement & Concrete Composites 33 (2011) 543-550 (“Zhang I”),claim that gap graded ternary blends of cement and SCMs may contain aslittle as 25% Portland cement and as high as 75% SCM. However, “thepreparation procedures of the gap-graded blended cements areconventionally viewed as being too complex for industrial practice” andproposed using “[c]ommercial Portland cements . . . manufactured by avertical roller mill,” which reduced the substitution level from 75% to55% compared to earlier gap graded ternary blends of the firstpublication. See Zhang, et al., “Influence of preparation method on theperformance of ternary blended cements,” Cement & Concrete Composites 52(2014) 18-26, 19 (“Zhang II”). In contrast, the use of a fineinterground particulate component, as disclosed herein, is a majordeparture from and is superior to the two different approaches taken byZhang et al. because (1) it is simple to make and suitable forindustrial practice, in contrast to the gap-graded blended cements ofZhang I, and (2) it permits a substantial reduction in the d90 of thehydraulic cement particles compared to OPC, in contrast to thegap-graded blended cements of Zhang II using OPC, in order to reduce oreliminate wasted cement particles that are too coarse to fully hydrate,even after months or years.

In addition, the fine interground particulate component permits theinclusion of finely ground SCM particles without requiring a separategrinding step as required in Zhang I and II. Combining the grinding offine hydraulic cement and SCM particles permits the manufacture of afine interground particulate component containing both materials in asingle milling process, which is industrially practical, in contrast tothe gap graded blends of Zhang I, and is more industrially practicalthan blending commercial Portland cement with a fine SCM, the entiretyof which must be processed separately from the Portland cement, as inZhang II. Moreover, to the extent that the SCM particles are softerand/or are more easily ground compared to cement clinker, the fineinterground particulate component can have an approximate bimodaldistribution in which the SCM particles are more concentrated in thefiner region of the PSD and the cement particles are more concentratedin the coarse region of the PSD of the overall interground component. Inthis way, the fine interground particulate component can more closelyresemble the fine SCM and narrow PSD cement components of the gap gradedternary blends of Zhang I, which permitted SCM substitution levels of upto 75%, rather than 55% when simply using OPC as a compromise measure asin Zhang II.

And even in those embodiments in which the fine interground particulatecomponent is not bimodal, it can still contain a substantial quantity ofvery fine SCM particles, which reduces the quantity of very fine cementparticles by dilution and thereby improves workability (e.g., bysignificantly increasing spacing between and reducing flocculation ofvery fine cement particles). Moreover, the fine interground SCMparticles are very reactive, either pozzolanically and/or as highquality nucleation sites that promote faster cement hydration. Finally,the fine interground particulate component includes hydraulic cementparticles with reduced d90 compared to OPC and conventional intergroundblended cement. This reduces or eliminates the preponderance of coarsecement particles that may never fully hydrate so that the hydrauliccement fraction can substantially fully hydrate within a standarddefined time period. This is not possible using OPC, conventionalinterground blended cement, conventional non-interground blends, orconventional self-blending methods at concrete plants.

The coarse particulate component provides coarse SCM particles thatcomplement the fine interground particulate component, raise the d90 ofthe overall cement-SCM blend or composition, and broaden the PSD of theoverall blend or composition compared to the fine intergroundparticulate component by itself. This permits the overall cement-SCMcomposition to have any desired PSD, such a PSD similar to, or evenbroader than, a Fuller distribution, which is conventionally viewed asbeing the ideal PSD of OPC (although modern grinding practices havesignificantly departed from the Fuller PSD model in favor of usingsteeper/narrower PSD cements in order to increase early strength).

By way of background, an ideal Fuller distribution is simply a powerfunction used to calculate the percent passing at any given particlesize of all particles in concrete, including both cement and aggregates,and has no defined upper and lower particle size limits although anarbitrarily defined maximum particle size can be used for each type ofparticle being considered (e.g., coarse aggregate, fine aggregate, andcement):

P(d)=(d/dmx)^(q)

-   -   where:        -   d=particle diameter        -   d_(max)=maximum particle diameter in the mixture        -   q=parameter (0.33-0.5) based on fineness or coarseness        -   P(d)=size cumulative distribution.

The assumed “ideal” power is about 0.45 but might be higher for finerparticle fractions, such as cement or blended cement. Because the Fullermodel contains no defined or “ideal” maximum cement particle size, onemust be assigned arbitrarily. In current practice, the d90 (or particlesize diameter with a percent passing of 90%) is typically selected to be45 μm, which is lower than cements used in the past, which weresignificantly coarser, had broader PSDs than modern OPC, and oftenyielded more durable concrete. Some of this is driven by the industrytrend of increasing the early strength development of OPC (e.g., becauseengineers most often specify 28-day strength, not long-term strength, asthe standard). It has been observed, however, that concrete that isdecades or even 100 years old is often stronger and more durable thannewer concrete made using finer cements. Thus, selecting a d90 of 45 μmis arbitrary and not dictated by the Fuller equation.

Another driving factor is the tendency of modern and more efficientmills, such as vertical roller mills and horizontal grinding rolls, toproduce narrow rather than broad PSD cement. Because narrow PSD cementsmade using modern mills often have fewer fine particles (e.g., FIG. 1B)compared to broader PSD cements (e.g., FIG. 1A), they further deviatefrom a modified Fuller distribution arbitrarily narrowed by lowering thed90. Thus, it may be necessary to further reduce the d90 just tomaintain the same “standard” Blaine number (e.g., 350-450 m²/kg) thatcustomers perceive to be ideal or desirable. Moreover, the current trendamong cement producers desirous of making “green cement” is to grindblended cements even more finely than OPC in an effort to boostreactivity and offset strength loss. As more cement producers adoptefficient modern mills, and especially if they produce more intergroundblended cements in an effort to appear “green”, the trend toward usingcement with ever-narrowing PSDs will continue, with little opportunityto reverse this trend, and with detrimental consequences as cementproducers sacrifice long-term durability for short-term strengthincreases and lower grinding costs.

The cement-SCM compositions, methods, and systems disclosed hereinprovide a way to escape this irreconcilably negative trend and theinherent technical limitation of modern grinding mills that prevent themfrom making broad PSD cements. This is accomplished by separatelyprocessing fine and coarse components of blended cements and othercement-SCM compositions. Combining a coarse particulate componentcomprising coarse SCM particles with a fine interground particulatecomponent comprising fine cement and fine SCM fractions is a majordeparture from conventional practices. It is a substantial improvementover the manufacture of interground cements, in which the cement clinkerand SCM are interground to the final desired Blaine fineness and/orfinal desired d90 and which typically have a higher Blaine and lower d90than OPC. It is also a substantial improvement over and major departurefrom conventional blending practices that blend OPC of standard finenesswith SCMs such as fly ash or GGBFS, which contain both coarse and veryfine SCM particles, and/or very fine and highly reactive SCMs such assilica fume or nano limestone, which contain no coarse SCM particles.The disclosed compositions, methods, and systems permit for simultaneousreduction in coarse cement particles that do not fully hydrate whilemaintaining or increasing the preponderance of coarse particles in theoverall cement-SCM composition.

In some embodiments, an optional auxiliary particulate component can beincluded in addition to the fine interground and coarse particulatecomponents. The optional auxiliary particulate component advantageouslyis not interground with either the fine interground particulatecomponent or the coarse particulate component. This permits the use ofsupplementary particles that may be readily available and can provideadditional properties as desired. The optional auxiliary particulatecomponent can be virtually any hydraulic cement, SCM material, or blendthereof that has not been interground with either the fine intergroundparticulate component or the coarse particulate component. By notintergrinding with either the fine interground particulate component orthe coarse particulate component, the optional auxiliary particulatecomponent provides maximum flexibility and permits fine adjustments tothe properties of the cement-SCM composition. For example, it may bedesirable to supplement the fine interground and coarse particulatecomponents with fine SCMs such as silica fume, which is known toincrease both early and late strengths but which is an industrialbyproduct of silicon and ferrosilicon manufacture and more expensivethan either hydraulic cement or conventional SCMs. And while it may beefficient to simply intergrind limestone as part of the fine intergroundparticulate component, it may be desirable, in some cases, to addadditional limestone, such as nano limestone, in order to increase therate of hydration and early strength formation.

In some cases, it may be desirable to supplement the fine intergroundand coarse particulate components with conventional OPC or otherhydraulic cement to increase the ratio of cement to SCM in thecomposition, such as to increase heat of hydration and/or early strength(e.g., in cold weather and/or where it is desired to remove forms and/orput the concrete into service more rapidly). In addition or instead ofadding hydraulic cement, it may be desirable to supplement the fineinterground and coarse particulate components with conventional SCMs,such as GGBFS and/or fly ash, in order to decrease the ratio of cementto SCM in the composition, such as to reduce heat of hydration (e.g.,when making thick concrete structures, such as drilling platforms usedin the oil and natural gas industries, bridge decks or structuralfootings and/or pillars) or otherwise increase SCM levels for anydesired reason.

The auxiliary particulate component may itself be an interground blendof cement and SCM, but which is not interground with either the fineinterground particulate component or the coarse particulate componentbut merely blended therewith. This permits the manufacture of differenttypes of interground components and blends, which can then be reblendedwith other blends in different ratios to obtain a wide range ofcement-SCM compositions having almost any conceivable range of desiredproperties.

In short, the ability to supplement the fine interground and coarseparticulate components with one or more auxiliary particulate componentspermits self-blending, as is customary in the concrete industry. It alsopermits a high degree of fine tuning to the extent that the fineinterground and coarse particulate components produce basic generalpurpose cement that can be used for many or most projects but whichcannot be optimized for every conceivable project or situation. In someembodiments, the cement-SCM compositions can be engineered to producehigher strength than the same quantity of OPC at the same or similar wcm. This permits the use of less overall binder in concrete to yield thesame strength and/or replacement of a portion of the cement-SCMcomposition with additional SCM.

A. Fine Interground Particulate Component

As used herein, the term “fine interground particulate component”includes a cement-SCM material that is made, at least in part, byintergrinding hydraulic cement (e.g., Portland cement clinker) with oneor more SCMs (e.g., slags, pozzolans, ashes, and fillers).Alternatively, the term “fine interground particulate component”includes first and second SCM components and is made, at least in part,by intergrinding a coarse SCM material (e.g., clinker or granules atleast 1-3 mm in size, such as metallurgical slag, limestone, geologicminerals, recycled pozzolans, e.g., glass, bricks, ceramics, etc.) withone or more other SCMs (e.g., which can be coarse or fine). As a generalrule with few, if any, exceptions, the fine component made byintergrinding two or more different materials will be significantlydifferent than the material produced by separately processing and thenblending the same two or more different materials together.

This is particularly true in the case of cement clinker, which typicallyhas multiple compounds (i.e., clinker minerals) that form separatecrystalline structures that are agglomerated together in each clinkernodule, and almost any SCM, which, by definition, is primarily not ahydraulic cement (although it may have some self-cementing properties ifit contains a sufficient quantity of calcium oxide) and will have verydifferent chemical and physical characteristics. Pozzolanic SCMs willcontain a substantial quantity of glassy, amorphous silica, which isgenerally not contained in cement clinker in significant quantities,and, with few exceptions, will contain little, if any, of the fourclinker minerals of Portland cement (GGBFS may contain calciumsilicates, but in much smaller amounts than cement clinker).Non-pozzolanic SCMs, such as limestone, will contain neither cementclinker minerals nor amorphous and pozzolanically reactive silica. ManySCMS, such as limestone and certain pozzolans, can be significantlysofter and more easily ground than cement clinker. Other SCMs, such asGGBFS, steel slags, and certain ashes, can be harder than cement clinkerand therefore harder to grind.

The probability that an SCM exists that will have the exact samegrinding characteristics as cement clinker, other selected hydrauliccement, or SCM granules is low. At the very least, the PSD of eachmaterial fraction within a fine interground particulate component willdiffer in some way compared to the same material if milled separately(e.g., with respect to at least one of the dl, d5, d10, d15, d25, d35,d50, d65, d75, d85, d90, d95, or d99). Such variations can beextrapolated by comparing the different PSDs of 100% cement clinker andinterground blends of the same cement clinker and natural pozzolan asillustrated in FIGS. 2A-4A. The variability even among different naturalpozzolans is quite evident by noting the very different morphologies andglassiness of the two natural pozzolans in FIGS. 5A and 5B, as well asthe observation that it was easier and required less energy tointergrind the pozzolan of FIG. 5A with cement clinker thanintergrinding the pozzolan of FIG. 5B with the same clinker and at thesame ratio of materials.

Moreover, intergrinding is believed to form a more intimate anduniformly blended mixture of two or more different components comparedto separate processing and simply blending. While separate processingand simple blending of coarse particles to yield a coarse blend mayachieve similar blending uniformity as intergrinding, that is not thecase with very fine materials, which contain orders of magnitude moreparticles than coarse materials. The extremely large number of particlescoupled with more particle-particle interactions in the case of fineparticulate materials, make blending uniformity much more difficult.Thus, intergrinding two or more components to yield a finely groundblend is far more likely to yield an intimate and uniformly blendedmixture than separate processing and simple mixing of the same finematerials.

Achieving a certain level of uniformity that is largely unachievablethrough simple blending can be particularly beneficial in the case ofblends of fine cement and SCM particles. One of the problems with thevery fine cement particles in OPC is their tendency to flocculate whenfirst mixed with water, which greatly increases viscosity and yieldstress and decreases flow and workability. Common ways to modifyconcrete having inadequate flow and workability include adding morewater, which substantially reduces strength by increasing thewater-to-cement ratio (w c) and can be harmful, adding a waterreducer/dispersant to at least partially deflocculate and disperse thecement particles, and/or introducing energy into the concrete by mixingor vibration. Intergrinding cement and SCM to yield a more intimatelymixed blend than is possible by separate processing and simple blendingcan be particularly beneficial where the fine SCM particles are capableof dispersing fine cement particles and reducing flocculation. WhileSCMs, such as fine fly ash, slag, or other pozzolans, can assist indispersing fine cement particles and reducing flocculation, thisbeneficial property is less pronounced when the cement and dispersingSCMs are not well mixed. In such cases, intergrinding should increasethe dispersing and deflocculating effect of fine cement particles by theSCM fraction compared to simple blending. This further demonstrates thatfine interground blends are qualitatively different than simple blendsof fine cement and SCM particles in addition to being physicallydifferent (e.g., in terms of PSD and/or morphology).

FIGS. 2B, 3B, and 4A are PSD charts showing data measured by a MalvernMastersizer 2000 of example fine interground particulate componentshaving hydraulic cement and SCM fractions, which can be used tomanufacture cement-SCM compositions as disclosed herein. The intergroundmaterial of FIG. 4B can be used as an auxiliary blending component. Forcomparison purposes, FIG. 2A is a PSD chart, illustratively subdividedwith fine, medium, and coarse fractions, showing data measured by aMalvern Mastersizer 2000, of a finely ground cement material consistingof 100% Portland cement made from the same batch of Drake cement usedfor the material of FIG. 1B and milled using the same Pfeiffer VRM.Interestingly, the PSD chart of FIG. 2A has a shape very similar to thePSD chart of FIG. 1B even though the two cements have very differentd90s. The finely ground cement material has a d90 of about 22.1 μm, ad50 of about 9.9 μm, and d10 of about 1.8 μm. Compared to the PSDs ofthe conventional Portland cement materials shown in FIGS. 1A and 1B, thefine cement of FIG. 2A has a substantially lower d90, higher reactivity,and substantially fewer particles, if any, that will not fully hydratewithin a standard defined time period (e.g., 28 days). This can bereadily seen by comparing the areas under the PSD curves correspondingto the “coarse” Portland cement fraction which, for illustrativepurposes, was selected here to be particles>30 μm.

The PSD of the finely ground cement material shown in FIG. 2A is similarto or characteristic of the PSD of Type III rapid hardening cement, asdefined by ASTM C-150. As a result, this material is generallyunsuitable as general purpose cement for use in making concrete, such asready mixed concrete, commonly used to manufacture large concretestructures such as drilling platforms, roads, driveways, sidewalks,bridges, buildings, and structural components of buildings. Rapidhardening cement is mainly used for specialty projects and ischaracterized by higher early strength and lower long-term strength. Itis used where it is critical to remove forms very quickly and/or wherethe concrete must be put into service very quickly (e.g., in less than 7days).

FIG. 2B graphically illustrates and compares the PSDs of the 100% groundPortland cement clinker of FIG. 2A (bold line curve) and a 50:50 (w/w)interground blend (thin line curve) of the same batch of Drake cementclinker and a natural pozzolan, also obtained from Drake Cement. The PSDchart in FIG. 2B of the 50:50 blend is apparently bimodal and is furthersubdivided to illustratively show fine, medium, and coarse fractions ofeach cement and pozzolan fraction. For illustration purposes, the PSDcurve of FIG. 2A, which is overlaid over the PSD chart for the 50:50blend, was used to extrapolate and estimate the relative proportions offine cement and pozzolan within the fine, medium, and coarse fractions.The PSD curve of the cement fraction in FIG. 2B was assumed to havesimilar shape as the PSD curves of FIGS. 1B and 2A, with the apparentbimodal feature being attributed to the different grindingcharacteristics of the softer natural pozzolan interground with thecement clinker.

The clinker and pozzolan were initially pre-blended and then milledusing the same Pfeiffer VRM. The interground blend has a d90 of about24.1 μm, a d50 of about 7.9 μm, and a d10 of about 1.5 μm. The PSD ofthe 50:50 (w/w) interground blend appears to have an approximate bimodalshape, which suggests a non-uniform distribution of cement and pozzolanparticles within the interground blend. Because the energy required toproduce the 50:50 (w/w) interground blend shown in FIG. 2B wassignificantly lower and the throughput was significantly higher than theenergy and throughput for the finely ground Portland cement clinkermaterial of FIG. 2A, it is postulated that this may be due to the easiergrindability of the natural pozzolan as compared to the cement clinker.This observation, coupled with the fact that the natural pozzolan wasfiner to begin with, suggests that the finer particles in the 50:50interground blend (e.g., below the d50) are predominately composed ofnatural pozzolan particles and the coarser particles (e.g., above thed50) are predominately composed of Portland cement particles.Classifying the interground blend at about 8 μm using a classifiercapable of making sharp cuts at this particle size, such as a highefficiency air classifier from Netzsch, and chemically analyzing andcomparing the fine and coarse fractions would confirm this.

For comparison purposes, FIG. 3A is a PSD chart, illustrativelysubdivided to show fine, medium, and coarse fractions, showing datameasured by a Malvern Mastersizer 2000 of another finely ground cementmaterial made from Drake cement using the Pfeiffer VRM. The finelyground cement material has a d90 of about 24.4 μm, a d50 of about 10.2μm, and d10 of about 2.1 μm. Compared to the PSDs of the conventionalPortland cement materials shown in FIGS. 1A and 1B, the fine cementmaterial of FIG. 3A has a substantially lower d90, higher reactivity,and substantially fewer particles that will not fully hydrate at 28days.

FIG. 3B graphically illustrates and compares the PSDs of the finelyground cement material of FIG. 3A (thin line curve) and another 50:50(w/w) interground blend (bold line curve) of Drake cement clinker andDrake natural pozzolan. The clinker and pozzolan were initiallypre-blended and then milled using the Pfeiffer VRM. The intergroundblend has a d90 of about 24.6 μm, a d50 of about 9.2 μm, and a d10 ofabout 1.8 μm. Similar to FIG. 2B, the PSD of the 50:50 (w/w) intergroundblend in FIG. 3B appears to have an approximate bimodal shape, althoughnot as distinctive as in FIG. 2B, which again suggests a non-uniformdistribution of cement and pozzolan particles within the intergroundblend. It is postulated that the finer particles in the 50:50interground blend (e.g., below the d50) are predominately composed ofnatural pozzolan particles and the coarser particles (e.g., above thed50) are predominately composed of Portland cement particles. Forillustration purposes, the PSD curve of FIG. 3A, which is overlaid overthe PSD chart for the 50:50 blend, was used to extrapolate and estimatethe relative proportions of cement and pozzolan within the fine, medium,and coarse fractions. The PSD curve of the cement fraction in FIG. 3Bwas assumed to have similar shape as the PSD curves of FIG. 3A, with theapparent bimodal feature being attributed to the different grindingcharacteristics of the softer natural pozzolan interground with thecement clinker. Classifying the interground blend at about 9 μm using aclassifier capable of making sharp cuts at this particle size andchemically analyzing and comparing the fine and coarse fractions wouldconfirm this.

FIG. 3C is a PSD chart of an interground blend of cement clinker andDrake natural pozzolan that does not have an apparent bimodal shape.Nevertheless, the shape of the PSD curve of the cement fraction wasassumed to have the same shape as the PSD curves in FIGS. 1B and 2A forthe same cement material. On this assumption, FIG. 3C is subdividedbetween cement and pozzolan materials throughout the PSD curve and stillshows a higher preponderance of fine pozzolan particles in the fineparticle region and a higher preponderance of cement particles in themedium and coarse particle regions even without an apparent bimodaldistribution within the overall interground blend.

FIG. 4A is a chart PSD of a 50:50 (w/w) interground blend of Drakecement and a different natural pozzolan (i.e., “west desert ash”)obtained from Jack B. Parsons Ready Mix, located in Utah, a subsidiaryof Oldcastle, Inc. The clinker and natural pozzolan were initiallypre-blended and then milled using the Pfeiffer VRM. This intergroundblend has a d90 of about 24.0 μm, a d50 of about 8.8 μm, and a d10 ofabout 1.9 μm. The PSD of this interground blend does not appear to havea bimodal shape, which might suggest a fairly uniform distribution ofcement and natural pozzolan particles throughout the interground blend.Alternatively, because the energy required to produce the 50:50 (w/w)interground blend shown in FIG. 4A was higher and the throughput lowerthan the energy and throughput for the interground blends of FIGS. 2Band 3B, it is possible this natural pozzolan is harder to grind thancement clinker. In such case, the interground blend might possibly havea higher preponderance of cement particles in the fine particle regionand a higher preponderance of pozzolan particles in the coarse particleregion. For purely illustrative purposes, the PSD chart is subdivided toshow the relative preponderance cement and pozzolan particles withinfine, medium, and coarse regions of the PSD curve.

FIG. 4B is a PSD chart of a 50:50 (w/w) interground blend of limestoneand the Parson natural pozzolan. The limestone and natural pozzolan wereinitially pre-blended and then milled using the same Pfeiffer VRM. Theinterground blend of limestone and natural pozzolan has a d90 of about24.2 μm, a d50 of about 6.3 μm, and a d10 of about 1.4 μm. The PSD ofthis interground blend has an approximate bimodal shape, which suggestsa non-uniform distribution of limestone and pozzolan particles withinthe interground blend. Because limestone is generally softer than cementclinker, because this natural pozzolan appears to be as hard or harderthan cement clinker, and because the PSD is broadened compared to theother illustrated PSDs, it is hypothesized that the finer particles inthis 50:50 interground blend (e.g., below the d50) are predominatelycomposed of limestone particles and the coarser particles (e.g., abovethe d50) are predominately composed of natural pozzolan particles. ThePSD chart was subdivided for illustrative purposes based on anextrapolation of the PSD curves shown in FIGS. 2A-4B. Classifying theblend at about 8 μm using a classifier capable of making sharp cuts atthis particle size, such as a high efficiency air classifier fromNetzsch, and chemically analyzing and comparing the fine and coarsefractions might confirm this. The inclusion of finely ground limestoneparticles can beneficially offset the retardation effect of manypozzolans in cement-SCM blends.

The PSDs of the interground blends in FIGS. 2B, 3B, and 4B suggest thatit may be possible to produce a fine interground particulate componenthaving an approximate trimodal distribution formed by three materials ofdifferent hardnesses, e.g., a first softer component (e.g., limestone)that predominates in the finest third of the overall PSD of the fineinterground particulate component, a second harder component (e.g.,natural pozzolan) that predominates in the in the intermediate third ofthe overall PSD, and a third hardest component (e.g., cement clinker)that predominates in the coarsest third of the overall PSD of the fineinterground particulate component.

FIG. 5A is a photograph made using a conventional microscope of sievedcoarse natural pozzolan particles provided by Drake cement, which is thepozzolan used to make the fine interground blended materials describedwith reference to FIGS. 2B, 3B, and 3C. The coarse particles appear tobe substantially opaque with a generally rounded and somewhat globularmorphology. Although the natural pozzolan particles are not sphericallike fly ash, their generally rounded morphology should permit them tobe a reasonably good coarse particulate SCM material for use in makingcement-SCM blends as disclosed herein. Some amount of classifying and/orsieving may be required to control the PSD. Coarse SCM particles havinga generally rounded morphology should in theory provide higher fluidityand lower water demand compared to more jagged particles. Nevertheless,because the pozzolan particles are not perfect spheres, they have someuneven surface that might provide for improved pozzolanic reactivity.Intergrinding with cement to make a fine interground particulatematerial as disclosed herein would likely significantly increase theirpozzolanic reactivity.

FIG. 5B is a photograph made using a conventional microscope of sievedcoarse natural pozzolan particles provided by Jack B. Parsons Ready Mix,which is the pozzolan used to make the fine interground blendedmaterials described with reference to FIGS. 4A and 4B. The coarseparticles have a glassy, more transparent appearance, suggesting anamorphous rather than crystalline structure and a jagged and more flatmorphology. The glassy and jagged nature of these particles mightincrease their pozzolanic reactivity compared to spherical pozzolanicparticles, such as fly ash, of similar size. However, their flat,plate-like morphology may reduce fluidity and increase water demandcompared to similarly sized particles having a rounded morphology. Someamount of grinding may produce a coarse particulate SCM material for usein making cement-SCM blends as disclosed herein. Intergrinding withcement to make a fine interground particulate material as disclosedherein would likely significantly increase their pozzolanic reactivity.

In some embodiments, the fine interground particulate component can havea d90 equal to or less than about 45 μm, 42.5 μm, 40 μm, 37.5 μm, 35 μm,32.5 μm, 30 μm, 27.5 μm, 25 μm, 23 μm, 21 μm, or 20 μm. In such cases,the d90 can be selected so as to be greater than about 10 μm, 11 μm, 12μm, 13 μm, 14 μm, 15 μm, 17 μm, or 19 μm. In other embodiments, the fineinterground particulate component has a d90 equal to or less than about25 μm, 23 μm, 21 μm, 19 μm, 17.5 μm, 16 μm, 15 μm, 14 μm, 13 μm, 12 μm,or 11 μm. In such cases, the d90 can be selected so as to be equal to orgreater than 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm.

In some embodiments, the fine interground particulate component can havea d10 equal to or less than about 5 μm, 4.5 μm, 4 μm, 3.5 μm, 3 μm, 2.75μm, 2.5 μm, 2.25 μm, 2 μm, 1.75 μm, 1.5 μm, 1.35 μm, 1.25 μm, 1.15 μm,1.07 μm, or 1 μm. In some embodiments, the d10 of the fine intergroundparticulate component can be equal to or greater than about 0.2 μm, 0.25μm, 0.3 μm, 0.35 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, or1.0 μm.

In some embodiments, the fine interground particulate component can havea d50 equal to or less than about 18 μm, 16 μm, 14.5 μm, 13 μm, 12 μm,11 μm, 10 μm, 9 μm, 8 μm, or 7 μm and/or equal to or greater than 4 μm,5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, or 12 μm.

In some embodiments, the hydraulic cement and SCM used to make the fineinterground particulate component can have different grindingcharacteristics so that the fine interground particulate component has aparticle size distribution (PSD) and includes a hydraulic cementfraction having a d50 (cement d50) and an SCM fraction having a d50 (SCMd50), wherein the cement d50 is either less than, equal to, or exceedsthe SCM d50. In some embodiments, the cement d50 exceeds the SCM d50 byat least about 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 4 μm, 5 μm, 6.5 μm, 8μm, 10 μm, 12 μm, or 14 μm. In some embodiments, the fine intergroundparticulate component can have a cement d50 to SCM d50 ratio greaterthan 1:3, 1:2.5, 1:2, 1:18, 1:1.65, 1:1.5, 1:1.4, 1:1.3, 1:1.25, 1:1.2,1:1.15, 1:1, 1.15:1, 1.2:1, 1.25:1, 1.3:1, 1.4:1, 1.5:1, 1.65:1, 1.8:1,2:1, 2.25:1, 2.5:1, 2.75:1, 3:1, 3.5:1, 4:1, 4.5:1, or 5:1.

In some embodiments, the SCM fraction of the fine intergroundparticulate component comprises at least about 5%, 10%, 15%, 20%, 25%,35%, 40%, or 45% and less than about 90%, 80%, 70%, 60%, or 50% byweight of the fine interground particulate component and/or thehydraulic cement fraction of the fine interground particulate componentcomprises at least about 10%, 20%, 30%, 40%, or 50% and less than about95%, 90%, 85%, 80%, 75%, 70%, 65%, or 55% by weight of the fineinterground particulate component.

In some embodiments, the fine interground particulate component furtherincludes gypsum, which can be included in an amount that is optimal forthe fine interground particulate component by itself or the overallcement-SCM composition. Alternatively, at least a portion of the gypsumrequired to regulate setting of the cement-SCM composition can beprovided as a separate component, such as by some or all of an auxiliaryparticulate component.

In some embodiments, the fine interground particulate componentcomprises at least about 15%, 20%, 25%, 30%, 35%, 40%, 50%, or 60% andless than 95%, 90%, 85%, 80%, 75%, 70%, or 65% of the combined fineinterground and coarse particulate components.

B. Coarse Particulate Component

As used herein, the term “coarse particulate component” means a materialthat is predominately or entirely composed of one or more SCM materialsand that is not interground with the fine interground particulatecomponent. The coarse particulate component can include any SCM materialthat is capable of partially replacing hydraulic cement in blendedcement and/or when making concrete. The coarse particulate component mayalso contain a lesser quantity of materials that may be considered to behydraulic cement, the only requirement being that the coarse particulatecomponent is not interground with the fine interground particulatecomponent. This is because separately processing the fine intergroundparticulate component and the coarse particulate component permits fortighter control of their respective PSDs. In this way, the cement andSCM materials can each be better optimized and more effectivelycontribute their respective beneficial properties to the overallcement-SCM composition. In addition, the coarse particulate componentcan have a PSD that complements the PSD of the fine intergroundparticulate component in order to broaden the overall PSD of thecement-SCM composition. This can be used to offset the inability of somemilling apparatus to produce a ground cement or blended blend having adesirably broad PSD.

Examples of coarse SCMs include coarse fly ash, such as out ofspecification fly ash, leftovers from classification, or dedusted flyash, ground metallurgical slags, steel slag, mine tailings, raw cementkiln feed (“raw meal” or “raw feed”), shale flue dust, bottom ash,ground waste glass, quarry fines from aggregate manufacturer, groundgeological materials, ground quartz, ground basalt, ground limestone,calcined and uncalcined clay, silts, sludges, red mud, rock dust, stonedust, marble dust, and the like.

The use of a separately processed coarse particulate component can atleast partially offset variability in cement quality that is oftenobserved with interground blended cements. Differences in thegrindability of multiple materials can cause differences in the PSD,which can be particularly problematic and difficult to control when thegrindability of one or more of the materials fluctuates unpredictablyover time. Providing a fine interground particulate component with alower d90 compared to conventional interground blended cements has beenobserved to reduce the differences between the PSDs of the differentfine sub-fractions in the interground blend, which should result in moreuniformity of a more finely ground interground blend than a coarseinterground blend when fluctuations in grindability occur. Greateruniformity is further provided by blending the fine intergroundparticulate component with the coarse particulate component, which isnot interground with the fine interground particulate component andwhich can therefore be processed to have a more tightly controlled PSD.Because it is impossible to control the PSD of a coarse SCM wheninterground with the fine components of a blended cement, separateprocessing of the coarse particulate fraction is perhaps the only, or atleast most predictable, way to reliably control the PSD of the coarseparticulate fraction and reduce or eliminate PSD variability.Accordingly, separately processing the fine interground particulatecomponent and independently controlling its PSD, particularly the d90,and also separately processing the coarse particulate component andindependently controlling its PSD, particularly the d10 and d90, bothcontribute to better control of the quality and properties of thecement-SCM composition compared to either intergrinding the entirematerial in a single process or simple blending of cement and SCMmaterials that are not particle size optimized to work well with eachother.

In some embodiments, a coarse particulate material of SCM particles canbe provided with a desired or acceptable d90 and d10 without furtherprocessing. In other embodiments, it may be possible or necessary togrind and/or classify and/or sieve an intermediate SCM material toreduce the d90 to within a desired range. In some embodiments, it may bepossible or necessary to “dedust” an intermediate SCM material, such asby using air classification and/or sieving apparatus known in the art,to increase the d10 to within a desired range. In other embodiment,commercially available SCMs, such as fly ash and GGBFS, can be used withlittle or no modification as the coarse particulate component.

In still other embodiments, the coarse particulate component maycomprise fly ash, slags other than GGBFS, bottom ash, or other SCMs thatwould otherwise be considered to be too coarse and/or unreactive toserve as a partial replacement for OPC. For example, in the case wherethe fine interground particulate component is more reactive than OPC, itmay be possible and even desirable to use a coarse and/or less reactiveSCM. The present invention therefore permits the use of SCMs that mightotherwise be discarded as undesirable, such as fly ash or otherpozzolans having a reactivity index that falls below a specified minimumstandard (e.g., ASTM C-618).

In cases where an SCM material is classified or dedusted to remove thefinest particles and raise the d10 to a desired level, the removed finematerial can be used for any purpose where fine SCMs are required ordesired. For example, the removed fine SCM particles can be sold as amicro silica material (e.g., as a silica fume substitute). Silica fumeand silica fume substitutes often have a market price exceeding theprice of OPC, thus providing a value-added way to beneficially utilizethe entire SCM material. In some cases, the removed fine SCM particlescan be further processed, such as through additional milling as needed,to further increase reactivity and market value.

Alternatively, the removed fine SCM particles can be used as part or allof the SCM feed material used to manufacture the fine intergroundparticulate component. Because the removed fine SCM particles arealready very fine to start with, using the removed fine SCM particles asa feed material can reduce grinding cost and/or throughput of the fineinterground particulate component and/or it may increase the propensityof forming a bimodal blend, with a higher concentration of fine SCMparticles in the finer PSD region of the fine interground particulatecomponent.

In some embodiments, the coarse particulate component can have a d10equal to or greater than about 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 8 μm,10 μm, 12 μm, 15 μm, 20 μm, 25 μm, 30 μm, or 35 μm and a d90 equal to orgreater than about 25 μm, 30 μm, 35 μm, μm, 50 μm, 60 μm, 75 μm, 100 μm,120 μm, or 150 μm and less than about 500 μm, 400 μm, 300 μm, 250 μm,200 μm, 175 μm, 150 μm, 125 μm, or 100 μm.

In some embodiments, the coarse particulate component has a d50 thatexceeds the d50 of the fine interground particulate component by atleast about 5 μm, 7.5 μm, 10 μm, 12.5 μm, 15 μm, 17.5 μm, 20 μm, 25 μm,30 μm, 35 μm, 40 μm, 45 μm, or 50 μm.

In some embodiments, the fine interground and coarse particulatecomponents form a dry blend, which can be distributed to one or moreconcrete plants and stored in a silo. In other cases, the fineinterground and coarse particulate components can be blended in situ,such as when manufacturing dry concrete containing aggregate or freshlymixed concrete that contains water, aggregate, and optionally one ormore chemical admixtures. For example, the fine interground particulatecomponent can be distributed to concrete plants as a premium cementblend that is combined with one or more of fly ash, slag, shale fluedust, mine tailings, ground slags, other SCMs, or OPC at the concreteplant. Alternatively, the fine interground particulate component can beused by itself as a substitute for Type III cement or other highlyreactive cement binder.

In some embodiments, the coarse particulate component comprises at leastabout 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50% and/or lessthan about 85%, 80%, 75%, 70%, 65%, 60%, 50%, 40%, 35%, 30%, 25%, or 20%of the combined fine interground and coarse particulate components.

C. Auxiliary Particulate Component(s)

In some embodiments, cement-SCM compositions may further include atleast one auxiliary particulate component, which is advantageously notinterground with either the fine interground particulate component orthe coarse particulate component. The auxiliary particulate componentcan be one or more of commercially available hydraulic cements, such asOPC, or commercially available SCMs, such as fly ash (Class C and/orClass F), GGBFS, metakaolin, silica fume, rapid hardening cement,supersulfated cement, magnesium cement, aluminate cement, low CO₂cement, low C3S and high C2S cement, calcium salt, magnesium salt, orgeopolymer cement.

In some embodiments, the auxiliary particulate component may includeauxiliary hydraulic cement, such as for example, hydraulic cement havinga d90 less than the d90 of the coarse particulate component and a d10less than the d10 of the coarse particulate component. In someembodiments, the d90 of auxiliary hydraulic cement may have a d90 thatis greater than, equal to, or less than the d90 of the fine intergroundparticulate component.

In some embodiments, the auxiliary particulate component may include anauxiliary SCM material, such as for example, a very fine particulate SCMmaterial having a d90 less than the d90 of the fine intergroundcomponent and/or a d10 less than the d10 of the fine intergroundcomponent. Examples include any of the various micro silica materialsknown in the art, such as silica fume, which is an industrial byproductformed during the manufacture of silicon and ferrosilicon materials. Avery fine auxiliary component may be desirable when the fine intergroundparticulate component is deficient in the quantity of very fineparticles, particularly very fine SCM particles (e.g., below 2 μm, whichare generally more desirable than cement particles below 2 μm; very finecement particles increase water demand and cement paste porosity whilevery fine SCM particles can reduce water demand and reduce pasteporosity).

In some embodiments, the auxiliary particulate component may include anauxiliary SCM material containing coarse SCM particles having a d90greater than the d90 of the fine interground particulate componentand/or greater than the d90 of the coarse particulate component. In somecases, the d10 of the auxiliary particulate component can be greaterthan the d10 of the fine interground particulate component and/orgreater than the d10 of the coarse particulate component.

The auxiliary particulate component may comprise ultra-coarse particles,such as unreactive fillers such as ground limestone, ground recycledconcrete, quartz, minerals, bottom ash, mine tailings, crystallinemetallurgical slags, or other industrial waste materials that havelittle or no reactivity and are well suited as a non-reactive filler.

The cement-SCM compositions may optionally include at least about 1%,3%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, or 40% and/or not more than about80%, 75%, 70%, 65%, 60%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, or 10%of an auxiliary particulate component.

III. Manufacture of Cement-SCM Compositions

The cement-SCM compositions disclosed herein can be made usingcommercially available milling, separating, and blending apparatus knownin the art, sometimes with modification in order to obtain blends andcompositions having a desired PSD. Non-limiting examples of millingapparatus include vertical roller mills, high pressure grinding rolls,horizontal roll presses, ball mills, rod mills, hammer mills, jaw mills,Raymond mills, jet mills, dry bead mills, ultrasonic fracturing mills,and the like. Non-limiting examples of separating apparatus includestand-alone classifiers, classifiers integrated with a vertical rollermill, and sieving apparatus. Non-limiting examples of blending apparatusinclude planetary mixers, dry rotating mixers, blade mixers, drystirring apparatus, dry shakers, and concrete mixing apparatus, such asconcrete mixing trucks and batch plant mixers. Examples of methods andapparatus for the manufacture and distribution of cement-SCMcompositions, or components thereof, are described in the followingpatent applications, which are incorporated by reference: U.S. Pat. Pub.No. 2012/0145046, Int'l Pat. Pub. No. WO 2012/075208, and U.S. patentapplication Ser. No. 13/357,121, filed Jan. 24, 2012, and entitled“Methods And Systems For More Efficient Utilization Of Cements AndSCMs.”

In some embodiments, a method of manufacturing a cement-SCM compositioncomprises: (1) intergrinding hydraulic cement (e.g., cement clinker)with one or more SCMs to form a fine interground particulate componentas described herein; (2) blending, without intergrinding, a coarseparticulate component as described herein and the fine intergroundparticulate component; and (3) optionally combining, withoutintergrinding, an auxiliary particulate component with the fineinterground particulate component and the coarse particulate component.

In some embodiments, a method of manufacturing a cement-SCM compositioncomprises: (A) intergrinding one or more clinkers or granules initiallylarger than about 1-3 mm with one or more finer particles or powdershaving an initial particle size less than about 1 mm to form a fineinterground particulate component; (B) blending, without intergrinding,the fine interground particulate component with a coarse particulatecomponent comprised of coarse SCM particles; and optionally (C) furthercombining, without intergrinding, an auxiliary particulate componentwith the fine interground particulate component and the coarseparticulate component. Where fine interground component (A) isinsufficiently hydraulically reactive, the auxiliary particulatecomponent may advantageously include hydraulically reactive particles.

In some embodiments, a method of manufacturing a cement-SCM compositioncomprises: (A) intergrinding (1) a first SCM component and (2) a secondSCM component to form a fine interground particulate component; (B)blending, without intergrinding, the fine interground particulatecomponent with a hydraulic cement component; and (C) blending, withoutintergrinding, the fine interground particulate component and thehydraulic cement component with a coarse particulate component; andoptionally (D) further combining, without intergrinding, an auxiliaryparticulate component (e.g., OPC, SCM, or other material) withcomponents (A), (B) and (C).

In order to ensure that the fine interground and coarse particulatefractions have respective PSDs within desired parameters, it istypically advantageous to periodically sample and accurately determineparticle size and PSD, such as by using particle size analyzers andtechniques known in the art. For example, PSD can be determined usinglaser diffraction techniques. An example of a particle size analyzerthat is commonly used to determine the PSD of cements and SCMs is aMalvern Mastersizer 2000. Another example is an online laser diffractionparticle size analyzer, such as the Malvern Insitec Fineness Analyzer,available from Malvern Instruments (Worcestershire, UK), which canautomatically take a series of PSD measurements of the product in realtime and, through a feedback loop, such information can be used tomodify the grinding and/or classification process to maintain the PSDwithin a desired range. Other methods for determining or estimatingparticle size include, but are not limited to, sieving, optical orelectron microscope analysis, x-ray diffraction, sedimentation,elutriation, microscope counting, Coulter counter, and Dynamic LightScattering.

In some embodiments, at least one of the intergrinding or blendingprocesses described herein can be performed at a cement plant thatincludes a kiln for producing the cement clinker. Such a process may beused, for example, to temporarily or permanently increase productioncapacity of an existing cement plant without having to build anexpensive new pyroprocessing system in parallel to an existing system.Whereas it may take many years to approve and build more clinkerproducing capacity at an existing cement plant, a grinding-blendfacility as described herein can be introduced at a cement plant withina much shorter time period. Not only would this permit a cement producerto meet increased market demand more quickly, it would increaseproduction capacity at much lower capital investment (e.g., at less than25%, 20%, 15%, or 10% the cost of a fully integrated cement facility).

Alternatively, at least one of the intergrinding or blending processescan be performed at a manufacturing facility that does not include akiln for producing cement clinker, such as a dedicated grinding and/orblending facility. According to some embodiments, the manufacturingfacility can be located at a concrete manufacturing plant, which is asignificant departure from conventional cement manufacturing methods.

In some embodiments, the manufacturing facility can be a dedicatedgrinding-blending facility that imports cement clinker from one or morecement plants, utilizes a local or inexpensively obtained SCM, anddistributes the cement-SCM composition to a plurality of concretemanufacturers. This is also a significant departure from conventionalcement manufacturing methods. A grinding-blending facility as describedherein is analogous to a mini-mill for reprocessing scrap iron andsteel, which is far more economical to build and operate than a fullyintegrated steel mill. And whatever may be the economic viability of adedicated grinding facility that grinds cement clinker and producesfinished cement more efficiently and at lower cost than purchasingfinished cement at market price from a fully integrated cement plant,further blending the cement clinker with one or more less expensive SCMsfurther improves the cost savings. Moreover, optimizing the particlesizes of the cement and SCM materials can reduce cost withoutsacrificing performance, as typically occurs when making conventionalblended cements.

Depending on the location of the dedicated grinding-blending facility,particularly where it is located at a terminal used to import cementclinker from great distances, the dedicated grinding-blending facilitycan be located at least 200, 300, 400, 500, 750, 1000, 2500, 5000, or10,000 miles from a cement plant from which it obtains clinker. Forexample, the dedicated grinding-blending facility is at or includes aterminal configured to receive clinker shipped by boat. By using alocally available SCM, the total net shipping cost and distance for theoverall cement-SCM composition can be greatly reduced compared to simplyproducing OPC from imported clinker.

In some embodiments, a method of manufacturing a fresh cementitiousmaterial comprises combining a cement-SCM composition as describedherein with water, aggregate, and optionally one or more admixtures. Thecement-SCM composition can be provided as a dry blend comprised of thefine interground particulate component, coarse particulate component,and optionally an auxiliary particulate component, stored in a dedicatedsilo, and dispensed into a mixing apparatus together with water,aggregate, and optionally one or more admixtures. Alternatively, thecement-SCM composition can be formed in situ by combining the fineinterground particulate component, coarse particulate component, andoptionally an auxiliary particulate component stored in separate silosand dispensed into a mixing apparatus together with water, aggregate,and optionally one or more admixtures.

In some embodiments, a method of manufacturing a hardened cementitiousmaterial from a cement-SCM composition comprises forming a freshcementitious mixture comprising a cement-SCM composition as describedherein and causing or permitting the fresh cementitious mixture toharden.

FIGS. 6-9 are flow charts that illustrate exemplary methods formanufacturing cement-SCM compositions and/or components thereof asdisclosed herein. FIG. 6 illustrates a basic method of manufacturing ablended composition (e.g., cement-SCM composition) 600 comprising: step602-intergrinding clinker (e.g., cement clinker) or granules (e.g.,metallurgical slag, aggregate, or ground mineral) and one or more SCMsto form a fine interground particulate component; step 604-forming orproviding a coarse particulate component that is not interground withthe fine interground particulate component; and step 606-blending thefine interground particulate component with the coarse particulatecomponent without intergrinding to form a blended composition (e.g.,cement-SCM composition). To this blended composition may optionally beadded one or more other additional components as disclosed herein, suchas hydraulic cement, SCM or other component, to yield a modifiedcement-SCM composition.

FIG. 7 illustrates a method of manufacturing a cement-SCM composition700 comprising: step 702-intergrinding cement clinker and one or moreSCMs to form a fine interground particulate component; step 704-formingor providing a coarse particulate component that is not interground withthe fine interground particulate component; step 706—dry blending thefine interground particulate component with the coarse particulatecomponent without intergrinding to form a dry blend; and step 708,optionally blending the dry blend with one or more of aggregate, water,or admixture. To the cement-SCM composition following either of steps706 or 708 can optionally be added one or more other additionalcomponents as disclosed herein to yield a modified cement-SCMcomposition.

FIG. 8 illustrates another method of manufacturing a cement-SCMcomposition 800 comprising: step 802—intergrinding cement clinker andone or more SCMs to form a fine interground particulate component; step804—forming or providing a coarse particulate component that is notinterground with the fine interground particulate component; and step806—blending the fine interground particulate component, the coarseparticulate component, and one or more of aggregate, water, oradmixture. To the cement-SCM composition, as part of or following step806, can be added one or more other additional components as disclosedherein to yield a modified cement-SCM composition.

FIG. 9 illustrates another method of manufacturing a cement-SCMcomposition 900 comprising: step 902-intergrinding clinker or granules,such as cement or SCM, and one or more SCMs to form a fine intergroundparticulate component; step 904-forming or providing a coarseparticulate component that is not interground with the clinker orgranules of used to make the fine interground particulate component;step 906-forming or providing an auxiliary particulate component, suchas hydraulic cement or SCM; and step 908-blending the fine intergroundparticulate component, the coarse particulate component, and theauxiliary particulate component without intergrinding to form thecement-SCM composition. To the cement-SCM composition can be added oneor more other additional components as disclosed herein to yield amodified cement-SCM composition.

Although some of the foregoing methods identify “cement clinker” isbeing interground with one or more SCMs to yield the fine particulatecomponent, it is understood that other granules or clinkers other thancement clinker can be used to form the fine particulate component, suchas one that includes a plurality of SCMs. In such case, the source ofhydraulic cement (e.g., OPC) can be blended with the fine particulatecomponent to yield a ternary blend of two separate feed streams. Thisblend can be blended with a coarse SCM without intergrinding to yield aquaternary blend of three different feed streams.

In some embodiments, a system of manufacturing a cement-SCM compositioncomprises: (A) one more milling apparatus configured to intergrindhydraulic cement (e.g., cement clinker) and one or more SCMs to form afine interground particulate component; (B) one or more blendingapparatus configured to blend, without intergrinding, the fineinterground particulate component with a coarse particulate componentcomprised of coarse SCM particles; and optionally (C) one or moreapparatus for combining, without intergrinding, an auxiliary particulatecomponent with the fine interground particulate component and the coarseparticulate component.

In some embodiments, a system of manufacturing a cement-SCM compositioncomprises: (A) one more milling apparatus configured to intergrind oneor more clinkers or granules initially larger than about 1-3 mm with oneor more finer particles or powders having an initial particle size lessthan about 1 mm to form a fine interground particulate component; (B)one or more blending apparatus configured to blend, withoutintergrinding, the fine interground particulate component with a coarseparticulate component comprised of coarse SCM particles; and optionally(C) one or more apparatus for combining, without intergrinding, anauxiliary particulate component with the fine interground particulatecomponent and the coarse particulate component. Where fine intergroundcomponent (A) is insufficiently hydraulically reactive, the auxiliaryparticulate component may advantageously include hydraulically reactiveparticles.

In some embodiments, a system of manufacturing a cement-SCM compositioncomprises: (A) one more milling apparatus configured to intergrind (1) afirst SCM component and (2) a second SCM component to form a fineinterground particulate component; (B) one or more blending apparatusconfigured to blend, without intergrinding, the fine intergroundparticulate component with a hydraulic cement component; and (C) one ormore blending apparatus configured to blend, without intergrinding, thefine interground particulate component and the hydraulic cementcomponent with a coarse particulate component; and optionally (D) one ormore apparatus for combining, without intergrinding, an auxiliaryparticulate component (e.g., OPC, SCM, or other material) withcomponents (A), (B) and (C).

FIGS. 10A and 10B schematically illustrate exemplary milling apparatusthat can be used to manufacture the fine interground particulatecomponent and, optionally, in the manufacture at least part of thecoarse particulate component and/or the optional auxiliary particulatecomponent.

FIG. 10A more particularly discloses a milling circuit 1000 thatincludes a transport conduit, conveyor, or apparatus 1002 configured todeliver a stream or mixture of particles, clinker and/or other materialto a mill 1004 that comminutes or otherwise reduces the particle size ofthe material to form a comminuted stream 1005. A separator 1006integrated with or separate from mill 1004 further processes comminutedstream 1005 and separates it into a coarse fraction 1008, which can becollected as product and/or recycled back to mill 1004 for furthercomminution, and a fine fraction 1010, which can be collected as productand/or intermediate material that is subjected to further processingusing known processing equipment, including, for example, processingequipment disclosed herein. Mill 1004 and/or separator 1006 can beadjusted or modified to produce a fine fraction 1010 having a desiredd90, d50, d10 and/or fineness.

Mill 1004 can be any mill used in the art of grinding or comminuting. Inthe case where mill 1004 and separator 1006 are independent rather thanintegrated apparatus, mill 1004 can be any known mill that does notinclude an integrated or internal separator. Non-limiting examplesinclude a ball mill, rod mill, horizontal roll press, high pressuregrinding roll, hammer mill, jaw mill, Raymond mill, jet mill, bead mill,high velocity impact mill, acoustic fracturing mill, and the like.Independent separator 1006 can be any known separator, such as a highefficiency air classifier, cyclonic separator, or sieving apparatus.

FIG. 10B more particularly discloses a vertical roller mill system 1020that includes a feed silo 1021 for storing and delivering a feedmaterial to be processed, metering equipment 1022, such as an auger, fordelivering feed material at a predetermined rate, and a vertical rollermill 1023, which receives feed material and mills it using a rotatingtable (not shown) and rotating stationary rollers (not shown) positionedabove the rotating table. A high efficiency classifier 1024 isintegrated with and positioned above vertical roller mill 1023. A hotgas generator 1025, which can be powered by natural gas, other fuel, orwaste heat from a cement kiln, produces hot gas, which is introducedinto vertical roller mill 1023 at a desired temperature, pressure andvelocity. The hot gases move upwardly around the outer perimeter of therotating table within vertical roller mill 1023, where they contactground particles expelled from the rotating table by centrifugal forceand carry at least a portion of the milled particles upward to highefficiency classifier 1024. The hot gases also dry the milled particles.Coarse particles (not shown) that are not carried by the upwardly movinggases to high efficiency classifier 1024 instead drop down below therotating table, where they are carried by a bucket elevator 1030, passedthrough a magnetic separator 1031, which separates a waste ironcontaining stream from a remaining portion of the coarse particles, andthe remaining portion is returned to vertical roller mill 1023 (e.g.,together with the feed material from feed silo 1021).

High efficiency classifier 1024 separates the milled particles receivedfrom vertical roller mill 1023 into a finer fraction, which is carriedby the upwardly moving gases to cyclone collector 1026, and a coarserfraction (not shown), which is dropped back onto the rotating table ofvertical roller mill 1023 for further milling. The d90 of the finerfraction can be controlled by modifying various parameters of thevertical roller mill system 1020, such as the rate at which the feedmaterial is introduced into vertical roller mill 1023, the pressureexerted on the rotating stationary rollers and transferred to thegrinding bed of particles, the speed and/or pressure of the hot gases,and the speed of a rotor containing fins or blades within highefficiency classifier 1024. The d90 can be periodically measured usingknown PSD-measuring equipment known in the art, such as alaser-diffraction measuring device. A mill fan 1027 assists in causingupward flow of hot gases through vertical roller mill 1023 and highefficiency classifier 1024 and separating milled product 1032 fromultrafine particles, which are collected by a filter 1028 and thencombined with milled product 1032 from cyclone collector 1026. A filterfan 1029 assists in moving the ultrafine particles from cyclonecollector 1026 toward filter 1028 and expels waste gases into the air.

FIG. 11 is a flow diagram that illustrates an exemplary method 1100 ofmanufacturing a coarse supplementary cementitious material comprising:step 1102-optionally grinding and/or classifying an initial SCM; step1104-dedusting the SCM to form a coarse SCM product; and step1106-optionally collecting the dedusted fine fraction and using it asdesired. For example, the dedusted fine fraction can be used as a microsilica component of concrete and/or blended cement and/or as an SCM feedcomponent for manufacturing the fine interground particulate component.The dedusting process can be performed using known apparatus, such as ahigh efficiency air classifier that is capable of making sharp cuts orseparations, a sieve apparatus, or combination thereof.

FIG. 12 schematically illustrates an exemplary separation apparatus1200, which can be used to manufacture one or more particulatecomponents, such as the coarse particulate component and, optionally, inthe manufacture of the fine interground particulate component and/or theauxiliary particulate component. The separation apparatus 1200 furtherincludes one or more separation mechanisms 1204 known in the art ofparticle separation, which receives a stream of particles 1202 andseparates the particles into at least a finer particle fraction 1206 anda coarser particle fraction 1208. The one or more separation mechanisms1204 may also be configured to produce other particle fractions, such asan intermediate particle fraction (not shown) that is less fine thanfiner particle fraction 1206 and/or less coarse than coarser particlefraction 1208. Examples of one or more separation mechanisms 1204include apparatus associated with a high efficiency classifier, acyclonic separator, sieving apparatus, or filter.

FIG. 13A schematically illustrates an exemplary system 1300 formanufacturing cement-SCM compositions as disclosed herein. System 1300more particularly includes at least a first storage silo or othercontainer 1302 for a pozzolan or other SCM and a second silo or otherstorage container 1304 for cement clinker, which can be raw or partiallymilled clinker or other hydraulic cement material, or other largeparticulate, clinker, or nodule material. Clinker(s) and SCM(s) fromstorage containers 1302, 1304 are processed according to methodsdisclosed herein and/or other methods known to those of ordinary skillin the art, such as by means of one or more grinders 1306 or othermilling apparatus and one or more classifiers 1308 or other separationapparatus to yield desired materials for making cement-SCM compositions.These include at least (1) a fine interground particulate componentcomprising a hydraulic cement fraction and an SCM fraction (or first andsecond SCM fractions), which can be stored within a fine intergroundparticulate silo 1310, and (2) a coarse particulate component comprisingcoarse SCM particles, which can be stored within a coarse particulatesilo 1312. In addition, an optional auxiliary particulate material canbe stored within an auxiliary particulate silo 1314.

In some embodiments, as indicated by the dotted arrow leading to coarseparticulate silo 1312, the coarse particulate component may be used asreceived without milling, dedusting or further processing (e.g., flyash, GGBFS, shale dust, mine tailings, raw feed for cement kiln, orother SCMs having a sufficient proportion of coarse particles thatcomplement the fine particulate component). While this may sometimesyield cement-SCM compositions that are less optimal than cement-SCMcompositions made using milled, dedusted or other further processedSCMs, simplification of the manufacturing process may justify thisoutcome (e.g., by reducing capital and/or operating costs of themanufacturing facility). In some embodiments, as indicated by the dottedarrow leading to auxiliary particulate silo 1314, the optional auxiliaryparticulate component may come pre-processed and need not be furtherprocessed by apparatus used to process the fine interground particulatecomponent and/or the coarse particulate component.

A blender 1316 can be used to blend the fine interground particulatematerial, coarse particulate material, and optional auxiliaryparticulate material to form a finished product, which, in the case of adry blended composition, can be stored within finished product silo1318. In other cases, blender 1316 can be a concrete mixer, such as astationary mixer used for mixing and batching concrete, or a concretemixing truck used to mix and transport concrete.

For example, FIG. 13B illustrates a modified system 1300 that includes ablender 1316 that is a stationary mixer used to make a dry blend orfresh concrete mixture that is then fed to a concrete delivery truck orvehicle 1320. If blender 1316 produces a dry blend, water and admixturescan be added directly to concrete delivery vehicle 1320 to form freshlymixed concrete, either at the concrete batch plant, during transport, orat the job site.

FIG. 13C illustrates yet another modified system 1300 in which theblending apparatus is a concrete delivery truck or vehicle 1320. Forexample, fine interground particulate silo 1310, coarse particulate silo1312, and optional auxiliary particulate silo 1314 can be located at aconcrete manufacturing plant for dispensing and mixing these materialdirectly within concrete delivery vehicle 1320. As in FIG. 13B, waterand admixtures can be added directly to concrete delivery vehicle 1320to form freshly mixed concrete, either at the concrete batch plant,during transport, or at the job site.

IV. Cementitious Products Made from Cement-SCM Compositions

In some embodiments, cement-SCM compositions disclosed herein can beused as general purpose or specialty cements in place of OPC and otherhydraulic cements known in the art. They can be used as sole orsupplemental binder to make concrete, ready mix concrete, baggedconcrete, bagged cement, mortar, bagged mortar, grout, bagged grout, oilwell cement, molding compositions, or other fresh or dry cementitiouscompositions known in the art. The cement-SCM compositions can be usedto manufacture concrete and other cementitious compositions that includea hydraulic cement binder, water and aggregate, such as fine and coarseaggregates. Mortar typically includes cement, water, sand, and lime andis sufficiently stiff to support the weight of a brick or concreteblock. Oil well cement refers to a cementitious composition continuouslyblended and pumped into a well bore. Grout is used to fill in spaces,such as cracks or crevices in concrete structures, spaces betweenstructural objects, and spaces between tiles. Molding compositions areused to manufacture molded or cast objects, such as pots, troughs,posts, walls, floors, fountains, ornamental stone, and the like.

V. Examples

The following examples are provided to illustrate example cement-SCMcompositions that can be made according to the disclosure. ComparativeExamples are also provided to assist in understanding differences andadvantages of the inventive cement-SCM compositions and the inventivemethods for making cement-SCM compositions compared to other blendedcements and methods for making blended cements.

In addition, an analysis of empirical data from the Comparative Examplesrelating the strength and workability was used by the inventor todevelop an analytical framework and proposed methodology for analyzingexisting blended cements and designing and manufacturing blended cementsand other cement-SCM compositions. The proposed analytical framework andmethodology includes: (1) the three fundamental optimization principlesdescribed above (Principles 1-3) for designing and producingwell-optimized blended cements; (2) the process described above foranalyzing different blended cements to determine how well they complywith the three fundamental principles to produce an optimization score;and (3) the process described above for predicting permissible SCMreplacement levels based on the optimization score. A description of howeach category of blended cement in the Comparative Examples was analyzedand assigned an optimization score is set forth below. A description ofhow these scores can be used to predict permissible SCM replacementlevels for other blended cements based on their optimization scores isalso provided.

As described below, the blended cements shown in the ComparativeExamples had SCM replacement levels of 20%, 35%, 55%, and 75%,respectively, with estimated assigned optimization scores of 2.0, 2.5,3.0, and 4.0, respectively. Coupled with a proposed baselineoptimization score of 1.0 for 100% OPC, the proposed analyticalframework provides a comparative tool that involves well-spaced SCMsubstitution levels ranging from 0-75% with well-spaced optimizationscores ranging from 1.0-4.0. Using the proposed analytical framework andmethodology, one can readily and accurately analyze the strengths andweaknesses of existing and proposed blended cements and other cement-SCMcompositions and then efficiently manufacture blended cements and othercement-SCM compositions.

Comparative Examples 1-20

Comparative Examples 1-20 describe the strength results of mortar cubetesting performed by the National Institute of Standards and Technology(NIST) according to ASTM C-109 on binary blends of separately processedand non-interground blends of hydraulic cement and fly ash. The w/cratio of the 100% cement control was 0.35. The same volume of water usedin the control mix was used in the blended cement mixes, sometimes witha high range water reducer (HRWR) to maintain flow. Because fly ash hasa lower specific gravity than cement, substitution was performed on avolumetric rather than a weight basis. The “volumes” of the fly ashcomponents were estimated by multiplying the weight of the fly ash at aproposed substitution level by the ratio of assumed specific gravitiesof fly ash to cement.

Examples 1-2 employed a commercially available Type I/II (ASTM C-150)cement to provide a control reference. The PSD chart of the controlcement is shown in FIG. 1A. Comparative Example 2 also employed acommercially available Class F fly ash (ASTM C-618) to provide areference control blend. Examples 3-19 each employed one of fourdifferent narrow PSD cements obtained by modifying the Type I/II cementof Examples 1 and 2 to have reduced d90 values (e.g., by classifying thecommercial cement to a target d90, regrinding the removed coarsematerial to the same target d90, and recombining the classified andreground fractions in proportions selected to maintain the samechemistry as the starting cement to yield the narrow PSD cement fortesting). Examples 3-18 each employed coarse Class F fly ashes obtainedby removing the coarsest particles by classification and then dedustingthe pre-classified fly ash to a target d10. Example 19 employed acommercially available Class C fly ash without modification. Example 20employed a coarse dedusted fly ash and a commercially available Type IIIcement to provide another control reference.

The measured d90 values for four modified cements were 9 μm (cement 10,“C10”), 11 μm (cement 9, “C9”), 12 μm (cement 8, “C8”), and 24 μm(cement 7, “C7”), in contrast to a d90 of 36 μm for the original cement(C6). The measured fly ash d10 values were 4 μm (fly ash 5, “F5”), 11 μm(fly ash 4, “F4”), 13 μm (fly ash 3, “F3”), and 15 μm (fly ash 2, “F2”),in contrast to 2.7 μm for the original fly ash (fly ash 1, “F1”). TheClass C ash is designated as “c ash”, and the Type III cement isdesignated as “C-III”. The d90 of the Type III cement was reportedlyabout 18 μm.

The cement and fly ash sample identities and the volumetric percentagesof cement and fly ash used in Examples 1-20 are set forth in Table 1below. Replacement of cement with fly ash was performed on a volumetricbasic to account for differences in the specific gravities of cement andfly ash. As a result, the water-to-cementitious binder ratios (w/cm) ofthe binary blends were higher than the w c of the control cement. Hadsubstitution been done on a weight basis while correspondingly reducingthe amount of sand, as is almost universally done in the cement industryand in test labs, the measured strengths of the binary blends would havebeen higher than those reported by NIST and reproduced in Table 1 below.

In some cases, a high range water reducer (HRWR) was added to maintainadequate flow without changing the volume of added water. The amounts ofHRWR, if any, are set forth in Table 1 and expressed in terms of weightpercent of total binder (e.g., 100 means 1 g per 100 g of total binder).

The 1-, 3-, 7-, 28-, 91-, and 182-day compressive strengths (MPa andpsi) of mortar cubes measured according to ASTM C-109 by NIST forExamples 1-20 are also set forth in Table 1.

TABLE 1 HRWR 1-day 3-day 7-day 28-day 91-day 182-day g/100 g (MPa) (MPa)(MPa) (MPa) (MPa) (MPa) Example Mix (%) cem (psi) (psi) (psi) (psi)(psi) (psi)  1 C6 100 0.00 36.7 54.4 63.6 80.3 84.7 86.0 5320 7900 922011640 12280 12470  1 repeat C6 100 0.00 36.3 55.1 62.7 79.4 87.9 92.65260 7990 9090 11510 12750 13430  2 C6 50 0.00 13.6 21.3 29.3 49.1 70.679.5 F1 50 1980 3090 4250 7120 10240 11520  3 C7 65 0.00 27.4 39.7 51.869.7 79.2 90.9 F3 35 3980 5780 7380 10100 11480 13170  4 C7 50 0.00 15.924.8 31.7 46.8 58.7 66.3 F2 50 2300 3600 4780 6790 8520 9620  5 C8 650.37 37.9 48.0 59.3 65.6 77.1 81.8 F2 35 5500 6960 8600 9510 11180 11860 6 C9 50 0.28 22.7 31.8 38.3 47.0 56.2 65.1 F4 50 3300 4620 5550 68208160 9450  7 C10 35 0.00 11.7 15.9 19.2 26.0 33.0 41.8 F2 65 1700 23102780 3770 4790 6060  8 C9 65 0.48 39.0 50.9 58.3 70.0 82.9 88.9 F5 355660 7380 8460 10150 12030 12890  9 C10 80 1.00 66.1 76.3 85.9 102 107105 F5 20 9590 11070 12460 14740 15510 15250 10 C10 65 0.67 44.6 53.464.8 72.4 80.6 83.3 F4 35 6460 7750 9400 10500 11690 12080 11 C8 35 0.0010.2 14.7 18.8 27.3 38.1 49.4 F4 65 1480 2130 2720 3960 5530 7160 12 C1050 0.05 25.2 33.7 40.7 49.4 57.6 63.3 F3 50 3650 4880 5910 7170 83609190 13 C7 80 0.05 36.7 50.8 63.5 78.1 89.8 91.8 F4 20 5320 7360 922011330 13020 13310 14 C8 80 0.80 53.6 68.5 80.1 89.7 93.9 99.6 F3 20 77709940 11620 13010 13620 14440 15 C7 35 0.00 8.41 14.6 18.3 30.5 47.7 57.0F5 65 210 2110 2660 4430 6910 8270 16 C8 50 0.05 22.3 32.1 40.1 51.664.9 71.6 F5 50 3240 4660 5810 7480 9410 10390 17 C9 80 1.00 54.5 66.778.4 92.9 94.3 96.2 F2 20 7910 9680 11370 13470 13680 13960 18 C9 350.00 10.2 14.8 19.1 25.7 35.7 46.2 F3 65 1480 2150 2770 3730 5180 671019 C9 65 0.67 38.8 51.4 61.4 79.6 85.9 90.9 C ash 35 5620 7460 891011540 12450 13180 20 C-III 65 0.48 31.8 45.6 49.6 66.3 77.6 84.2 F5 354611 6620 7197 9620 11260 12207

The compressive strength results indicate that the binary blends testedby NIST, which did not contain an interground cement-SCM component, wereable to achieve adequate strength compared to the 100% control cement atsubstitution levels of 20% and 35%. At a substitution level of 20% (80%cement, 20% fly ash), the high fineness of the cement component causedsignificant water demand issues, particularly as the cement becamefiner, requiring the use of a high range water reducer (HRWR) to obtainadequate flow, as required by ASTM C-109. Cement 10 was so fine that the80-20 blend (Example 9) could not achieve adequate flow even with HRWR,had high shrinkage, and was considered by NIST to be a flawed material.Even at 35% substitution, only cement 7 was able to form a binary blendthat did not require HRWR (Example 3), but that blend did not have highearly strength like the other 65-35 blends (Examples 5, 8, 10), whichrequired a significant quantity of HRWR. At substitution levels above35%, namely 50% (Examples 2, 4, 6, 12, 16) and 65% (Examples 7, 11, 15,18), none of the binary blends was able to match the strengthperformance of the control cement at any test day. The 65-35 binaryblend using commercially available Type III cement (Example 20) largelyunderperformed the 65-35 blends made using cements 7-10 (Examples 3, 5,8, 10, and 19) in most respects, with a few exceptions.

Baseline Optimization Score—100% OPC

The Control Cement used in Comparative Examples 1-2 was commerciallyavailable Type I-IT OPC with a d90 of 40-45 μm, d10 of 1-2 μm, and PSDnarrower than a Fuller distribution. as illustrated by the PSD chart ofFIG. 1A. A representative OPC having an even steeper PSD is illustratedin the PSD chart of FIG. 1B. The representative 100% OPC compositionsillustrated by the PSD charts in FIGS. 1A and 1B violate Principles 1and 2 because the cross-hatched areas labeled “fine PC” (e.g.,particles<5 μm) and “coarse PC” (particles>30 μm) consist entirely ofPortland cement particles. The OPC compositions are in substantial (butnot total) compliance with Principle 3 because the PSDs, though broad,are substantially narrower than a Fuller distribution. The optimizationscore for the OPC in FIG. 1A is estimated to be 1.0 (0.0+0.0+1.0). Theoptimization score for the OPC in FIG. 1B is also estimated to be 1.0(0.0+0.25+0.75). The score for Principle 2 in the OPC of FIG. 1B wasincreased to 0.25.0 because of the reduced quantity of fine particlesbelow 0.5 μm compared to the OPC of FIG. 1A; however, the score forPrinciple 3 was reduced to 0.75 because of the steeper PSD curve shownin FIG. 1B, which deviates more from a Fuller distribution than the PSDcurve of FIG. 1A. This illustrates how different cements can be equallysuboptimal for SCM substitution for different reasons under the proposedanalytical framework.

The low optimization score for OPC also illustrates why simple blendedcements consisting of OPC and separately processed SCM can show a dropin strength, particularly early strength, when compared to 100% OPC ateven modest substitutions in OPC of 15-25%. Indeed, the 50:50 blend ofExample 2 using OPC had lower early (1-7 day) strengths compared to eachof the 50:50 binary blends of Examples 4, 6, 12 and 16, particularly the1-day strength. For this reason, it is customary to increase the totalbinder content in concrete to make up for the drop in early strength(e.g., 500 lbs. of 100% OPC in a cubic yard of concrete might bereplaced with 600 lbs. of blended cement consisting of 400 lbs. of OPCand 200 lbs. of fly ash).

Optimization Score—80% cement, 20% SCM

The binary blend of Comparative Example 13 was analyzed using theanalytical framework to determine the optimization score for binaryblends having 20% SCM because it had a strength and water demand thatmost resembled the strength and water demand of the Control Cement ofComparative Example 1. The binary blend of Comparative Example 13 usedcement 7, which had a d90 of 24 μm, and is therefore in substantial, butnot total, compliance with Principle 1 due to the small but notinsignificant fraction of coarse cement particles>24 μm. It violatesPrinciple 2 due to the large amount of very fine cement particles<8 μm.It substantially, but not entirely, complies with Principle 3 becausethe coarse fly ash particles of fly ash 4 blended with cement 7broadened the overall PSD of the binary blend, but not to the extent ofa Fuller distribution. The estimated score is 2.0 (1.0+0.0+1.0), whichexplains why this binary blend had similar strength at all ages comparedto the Control Cement consisting of 100% OPC of Example 1, which is animprovement over simple blends of 80% OPC and 20% fly ash, whichtypically show a loss of early strength compared to 100% OPC.

Optimization Score—65% Cement, 35% SCM

The binary blend of Comparative Example 19 was analyzed using theanalytical framework to determine the optimization score for binaryblends having 35% SCM because it had a strength that most resembled thestrength of the Control Cement of Comparative Example 1. The binaryblend of Comparative Example 19 used cement 9, which had a d90 of 11 μm,which fully complies with Principle 1 due to the elimination of coarsecement particles that do not fully hydrate. It violates Principle 2 dueto the very large amount of very fine cement particles<8 μm. Itsubstantially, but not entirely, complies with Principle 3 because thefly ash particles broaden the overall PSD of the blend, but not to theextent of the desired Fuller distribution. The estimated score is 2.5(1.5+0.0+1.0), which explains why this binary blend had similar strengthat all ages compared to the Control Cement consisting of 100% OPC ofExample 1 at 65% cement and 35% fly ash and had higher SCM contentcompared to the binary blend of Comparative Example 13 with a score of2.0. The score of 2.5 also explains why the binary blend ComparativeExample 19 is a substantial improvement over simple blends of 65% OPCand 35% fly ash, which typically show a substantial loss of earlystrength and a drop in later strength when compared to 100% OPC.

Examples 21-38

Each of Comparative Examples 3-20 is modified by replacing the cementcomponents (cements 7-10 and Type III cement) with an interground blendof Portland cement clinker and pozzolan (e.g., one or more of coal ash,natural pozzolan, or metallurgical slag) ground to the same d90 as thecement component in the corresponding Comparative Example. In addition,each of Comparative Examples 3-20 is modified by reducing the amount ofcoarse pozzolan in order to maintain the same overall percentsubstitution of SCM. The amounts of cement clinker and pozzolan in thefine interground particulate component and also the amounts of fineinterground particulate component and coarse particulate component areprovide below in Table 2. The “blend type” refers to the percent of eachof the fine and coarse components (e.g., 80% fine and 20% coarse has ablend type designated as “80/20”). The relative amounts of the cementfraction and pozzolan fraction in the fine interground component of eachExample was selected to provide a cement-pozzolan blend with predictedwater demand and HRWR requirements similar to or less than in thecorresponding Comparative Example.

TABLE 2 Example Fine Cement Pozzolan Coarse (d90 CorrespondingInterground Fraction Fraction Particulate of fine Comparative Component(% of (% of Component compo- Example (% of IG IG (% of nent) (BlendType) whole) Comp.) Comp.) whole) 21 13 86.0 93 7 14.0 (24 μm) (80/20)22  3 76.5 85 15 23.5 (24 μm) (65/35) 23  4 69.5 72 28 30.5 (24 μm)(50/50) 24 15 63.6 55 45 36.4 (24 μm) (35/65) 25 14 84.2 95 5 15.8 (12μm) (80/20) 26  5 76.5 85 15 23.5 (12 μm) (65/35) 27 16 69.5 72 28 30.5(12 μm) (50/50) 28 11 63.6 55 45 36.4 (12 μm) (35/65) 29 17 84.2 95 515.8 (11 μm) (80/20) 30  8 76.5 85 15 23.5 (11 μm) (65/35) 31 19 76.5 8515 23.5 (11 μm) (65/35) 32  6 69.5 72 28 30.5 (11 μm) (50/50) 33 18 63.655 45 36.4 (11 μm) (35/65) 34  9 84.2 95 5 15.8  (9 μm) (80/20) 35 1076.5 85 15 23.5  (9 μm) (65/35) 36 12 69.5 72 28 30.5  (9 μm) (50/50) 37 7 63.6 55 45 36.4  (9 μm) (35/65) 38 20 76.5 85 15 23.5 (18 μm) (65/35)

The cement-SCM compositions according to Examples 21-38, when testedaccording to ASTM C-109 and made with the same water-to-cementitiousbinder ratio (w/cm) used in each of Comparative Examples 3-20, arepredicted to have higher early (1- to 7-day) and long-term (28- to182-day) strength, the same or better water demand and flow, the same orlower HRWR requirement, and the same or higher long-term durabilitycompared to each corresponding Comparative Example, which were madeusing a fine cement not interground with pozzolan.

With regard to strength, because each of Examples 21-38 contains ahigher quantity of fine pozzolan, a lesser quantity of coarse pozzolan,and the same quantity of fine cement in comparison to each correspondingComparative Example, it is predicted, based on the principles disclosedherein, that Examples 21-38 will have higher early and long-termstrengths (e.g., because they will have higher pozzolanic reactivity atall ages and no corresponding reduction in cement reactivity).

The beneficial effects of increased early and long-term strength will bemore pronounced with increasing pozzolan content (i.e., because of theprogressively increasing fine-to-coarse pozzolan ratio permitted athigher pozzolan substitution levels because, in the ComparativeExamples, water demand problems decreased with increasing pozzolansubstitution levels). For example, the 80/20 blends of Examples 25, 29,and 34 have a fine-to-coarse pozzolan ratio of 0.27:1, as compared to0.49:1 for the 65/35 blends, 0.64:1 for the 50/50 blends, and 0.79:1 forthe 35/65 blends.

The 80/20 blend of Example 21 is an anomaly due to the low water demandand HRWR requirement of Comparative Example 13 and can therefore bepermitted to have a substantially higher fine-to-coarse pozzolan ratiocompared to the other 80/20 blends (0.58:1 versus 0.27:1). As a result,it is predicted that the relative strength increase of Example 21compared to corresponding Comparative Example 13 would be greater thanin Examples 25, 29, and 34 since each of their corresponding ComparativeExamples already had strengths that far exceeded the strength of the100% control blend at all ages. Therefore, not only will intergrindingcement and pozzolan to form a fine interground particulate componentbeneficially increase early and long-term strengths with increasingpozzolan content in comparison to the Comparative Examples, as explainedin the previous paragraph, it will dramatically increase strengthrelative to Comparative Examples using non-interground fine cementfractions with higher d90, which have lower water demand, lowerreactivity, and lower strength to begin with compared to cementfractions having lower d90. Such differing trends in the beneficialeffect on strength of using a fine interground particulate componentinstead of a non-interground fine cement devoid of fine intergroundpozzolan particles, are surprising and unexpected in the absence of theknowledge and understanding provided herein.

With regard to water demand, flow and HRWR requirement, the inclusion offine pozzolan particles interground with fine cement particles will, allthings being equal, increase interparticle spacing between and reduceflocculation of the fine cement particles. It is predicted that thebeneficial effects of the fine interground pozzolan relating to waterdemand, flow and HRWR requirement will substantially offset any negativeeffects on these variable that may be caused by reducing the quantity ofcoarse pozzolan particles in the overall composition. To the extent thatone or more of Examples 21-38 results in increased water demand and HRWRrequirement relative to their corresponding Comparative Examples, one ofskill in the art, with the aid of the teachings disclosed herein, couldmodify any of such examples, such as by altering the relative quantitiesof hydraulic cement and pozzolan in the fine interground particulatecomponent and/or modifying the amount of the coarse pozzolan componentin the cement-SCM composition in order to achieve similar or lower waterdemand and HRWR requirement compared to the corresponding ComparativeExample(s). Conversely, to the extent that that one or more of Examples21-38 results in decreased water demand and HRWR requirement relative totheir corresponding Comparative Examples, other modifications could bemade to increase water demand and/or HRWR requirement to within anacceptable level with the aim of increasing strength or other beneficialproperty.

With regard to long-term durability, it is predicted that the inclusionof fine pozzolan particles interground with fine cement particles willincrease cement paste density and reduce chloride ion permeability, bothof which will beneficially increase durability.

Example 39

Any of Examples 21-38 is modified by replacing some or all of thePortland cement clinker with one or more hydraulic cements known in theart, including any of the hydraulic cements disclosed herein. Comparedto a control cementitious composition comprising hydraulic cement andpozzolan or other SCM, the modified cement-SCM compositions made using afine interground particulate component comprising a hydraulic cementfraction and an SCM fraction together with a coarse particulatecomponent comprising coarse SCM particles will achieve higher strengthcompared to the control cementitious composition.

Example 40

Any of Examples 21-39 is modified by replacing a portion of the pozzolanin the fine interground particulate component with an amount oflimestone sufficient to increase heat of hydration and/or early strengthof the cement-SCM composition. For example, to the extent that any ofExamples 21-39 has adequate long-term strength (e.g., similar to orhigher than a 100% control cement) but has inadequate early strength,adding finely ground limestone can beneficially increase early strengthwhen so desired. Because limestone may reduce long-term strength, theaddition of limestone will be more suitable for cement-SCM blends havinghigher long-term strength compared to the control cement. In such cases,an amount of limestone can be added that will reduce the long-termstrength to the same level as the control cement while beneficiallyincreasing early strength. In this way, the strength curve of themodified cement-SCM composition can more closely resemble the strengthcurve of the control cement compared to the cement-SCM blend devoid oflimestone.

Example 41

Any of examples 21-40 is modified by adding, without intergrinding withthe fine interground particulate component and the coarse particulatecomponent, one or more auxiliary particulate components known in the artand/or as disclosed herein in order to modify the properties of thecement-SCM composition. For example, one or more of silica fume, OPC,finely ground cement, blended cement, GGBFS, finely ground limestone, orfly ash can, without further modification, be combined with thecement-SCM composition of any of Examples 1-40 to form a modifiedcement-SCM composition having desired properties.

Example 42

Any of examples 21-41 is modified by adding an amount of a calcium-basedset accelerator, such as calcium oxide (CaO), calcium chloride (CaCl₂)),calcium nitrite (Ca(NO₂)₂, or calcium nitrate (Ca(NO₃)₂ and/or an alkalimetal salt capable of increasing the pH of the mix water, such as sodiumhydroxide (NaOH), sodium citrate, or other alkali metal salt of a weakacid. The calcium ions provided by the calcium-based set acceleratorwill not only accelerate hydration of the hydraulic cement fraction ofthe cement-SCM composition (e.g., in cold weather or other situationswhere it is desired to increase early strength), they can beneficiallyreact with silicate ions from the pozzolan to form additional cementbinder products. Alternatively, or in addition, the increased pHprovided by the alkali metal salt can accelerate the pozzolanic reactionby accelerating dissolution of silicate ions and/or aluminate ions fromthe pozzolan and making them more readily available for reaction withcalcium and/or magnesium ions provided by the hydraulic cement fraction.

Comparative Examples 43-49

Five gap graded ternary blends were prepared according to Zhang, et al.,“A new gap-graded particle size distribution and resulting consequenceson properties of blended cement,” Cement & Concrete Composites 33 (2011)543-550. Each of the five gap graded ternary blends, designated hereinas Comparative Examples 43-47, was prepared so as to have threefractions designed as “fine” (<8 μm), “middle” (8-32 μm), and “coarse”(<32 μm) fractions, in which a fine SCM, a narrow PSD cement, and acoarse SCM were arranged in the fine, middle, and coarse fractions,respectively, and in amounts of 36%, 25%, and 39%, respectively, toyield gap graded blends containing 25% cement and 75% total SCM. Thefine, middle, and coarse fractions were each made by classifying abroader PSD starting material to yield a fraction having the desiredPSD.

The middle fraction in each of Examples 43-47 consisted of a narrow PSDcement clinker. Example 43 included GGBFS in the fine and coarsefractions and was designated as “BCB”. Example 44 included GGBFS in thefine fraction and Class F fly ash in the coarse fraction and wasdesignated as “BCF”. Example 45 included GGBFS in the fine fraction andsteel slag in the coarse fraction and was designated as “BCS”. Example46 included GGBFS in the fine fraction and limestone in the coarsefraction and was designated as “BCL”. Example 47 included steel slag inthe fine and coarse fractions and was designated as “SCS”.

A control “Portland cement”, designated herein as Comparative Example48, consisted of 100% OPC made using the same cement clinker used tomake the narrow PSD cement in Examples 43-47. A control “referencecement”, designated herein as Comparative Example 49, consisted of asingle interground blend of the same GGBFS, cement clinker, and fly ashmaterials used to make the gap graded cement of Example 44. Neither thePortland cement nor the reference cement of Examples 48 and 49 hadseparate fine, middle, and coarse fractions and were not “gap graded”.

The relative water requirements for attaining normal consistency (flow)of the gap-graded cements, Portland cement (“PC”), and reference cement(“RC”) of Examples 43-49 were reportedly as follows:

RC»BCF>BCB>BCL>BCS>SCS>PC.

The relative 3-day compressive strengths for Examples 43-49 werereportedly as follows:

PC>BCB>BCS>BCF>BCL>SCS»RC.

The relative 28-day compressive strengths for Examples 43-49 werereportedly as follows:

PC>BCS>BCB>BCF>SCS>BCL>RC.

The relative 3-day flexural strengths for Examples 43-49 were reportedlyas follows:

BCB>BCS>PC>BCF=BCL>SCS»RC.

The relative 28-day flexural strengths for Examples 43-49 werereportedly as follows:

BCB>BCL>BCS>BCF=PC=SCS»RC.

The relative particle packing densities for Examples 43-49 werereportedly as follows:

BCS>BCB>SCS>BCL>BCF»PC>RC.

The reference cement, made by intergrinding all of the componentstogether to form a single interground blend that did not containseparate fine, middle, and coarse fractions, performed the worst inevery tested category. The reference cement had the highest water demandand the lowest strength. The reference cement also had the lowest rateof heat evolution and heat of hydration, both of which are negative, andthe highest porosity and pore diameter, which are also negative. Thisdata suggest that conventional blended cements made by intergrinding allcomponents together to form a single blended material are suboptimal.Nevertheless, there has been no obvious effort by the cement industry toremedy this problem other than simply blending OPC and one or more SCMstogether without any intergrinding. In neither case—intergrindingeverything together or intergrinding nothing together—is there anydemonstrated understanding as to the benefits of combining separatelyprocessed fine and coarse fractions having complementary, rather thansubstantially overlapping, PSDs.

On the other hand, the gap graded blends of Examples 43-47 made fromseparately processed fine, middle, and coarse fractions and without anyintergrinding, demonstrated that blended cements having up to 75% SCMcontent and as little as 25% Portland cement content can perform similarto 100% OPC. The main problem with the gap graded blends of Examples43-47 is that they are, according to Zhang, et al., “conventionallyviewed as being too complex for industrial practice”. This is likely dueto the fact that the authors do not propose, nor seem to be aware of,any economically feasible way to manufacture the fine, middle, andcoarse fractions required to make the gap graded cements, particularlythe narrow PSD cement constituting the middle fraction.

Optimization Score—25% cement, 75% SCM

The gap-graded ternary blends of Comparative Examples 43-47substantially comply with Principles 1 and 2 because the fine and coarseparticles mainly consist of SCM particles and are substantially devoidof Portland cement particles. The gap-graded ternary blends alsosubstantially comply with Principle 3 because the overall PSD of theblend approximates a Fuller distribution even though it consists ofthree separate fractions with narrow but complementary PSDs. Theestimated score approaches 4.0 (1.5+1.0+1.5) because the gap-gradedternary blends of Comparative Examples 43-47 had the highest SCMsubstitution levels of any studied example.

Comparative Examples 50-59

To remedy the perceived difficulties with the gap graded cements ofComparative Examples 43-47, five (5) additional gap graded cements weremanufactured using a commercial Portland cement having a standard Blainefineness (350 m²/kg) and a PSD that was somewhat narrower than a Fullerdistribution in place of the narrow PSD cement used in ComparativeExamples 43-47. The Portland cement contained 95% ground cement clinkerand 5% gypsum. The five additional gap graded cements, designated asComparative Examples 50-54, are described in Zhang, et al., “Influenceof preparation method on the performance of ternary blended cements,”Cement & Concrete Composites 52 (2014) 18-26.

As in Comparative Examples 43-47, the gap graded blends of ComparativeExamples 50-54 included a fine SCM fraction (<8 μm) and a coarse SCMfraction (>32 μm) in addition to commercial Portland cement middlefraction. However, the amounts of the SCM components were reduced suchthat the modified gap graded cements of Examples 50-54 included 25% SCMin the fine fraction, 35% SCM in the coarse fraction, and 45% Portlandas a modified middle fraction, which yielded gap graded blendscontaining 45% cement and 55% SCM. For comparison purposes, fivecorresponding interground blends, designated as Comparative Examples55-59, were made from the same materials used in correspondingComparative Examples 50-54.

Example 50 included GGBFS in the fine and coarse fractions and wasdesignated as “G_(BCB)”. Example 51 included GGBFS in the fine fractionand Class F fly ash in the coarse fraction and was designated as“G_(BCF)”. Example 52 included GGBFS in the fine fraction and steel slagin the coarse fraction and was designated as “GBCS”. Example 53 includedGGBFS in the fine fraction and limestone in the coarse fraction and wasdesignated as “G_(BCL)”. Example 54 included both GGBFS (20% of totalcement) and Class F fly ash (5% of total cement) in the fine fractionand Class F fly ash in the coarse fraction and was designated as“G_((B+F)CF)”.

Examples 55-59 were made by intergrinding the same SCM and Portlandcement materials used to make Examples 50-54, respectively, and weredesignated as Example 55: “I_(BCB)”; Example 56: “I_(BCF)”; Example 57:“IBCs”; Example 58: “I_(BCL)”; and Example 59: “I_((B+F)CF)”. The waterrequirement for normal consistency were reportedly about the same forthe gap graded and interground blend and therefore were not an issue.The compressive and flexural strengths of the gap graded blends ofExamples 50-54 were similar to the compressive and flexural strengths of100% OPC (e.g., Comparative Example 48) but far superior to thecompressive and flexural strengths of the interground blends of Examples55-59, as shown in Table 3.

TABLE 3 Compressive Flexural Cement Strength (MPa) Strength (MPa)Example ID 3-day 28-day 3-day 28-day Gap Graded Blended Cements 50G_(BCB) 26.5 49.2 6.8 9.8 51 G_(BCF) 25.6 47.3 6.5 9.7 52 G_(BCS) 26.648.2 6.8 9.3 53 G_(BCL) 22.7 44.8 5.1 9.1 54 G_((B + F)CF) 24.9 45.5 6.49.4 Interground Blended Cements 55 I_(BCB) 16.1 37.9 3.9 8.6 56 I_(BCF)13.7 34.5 3.5 8.5 57 I_(BCS) 13.5 33.6 3.4 8.1 58 I_(BCL) 8.9 27.9 2.77.8 59 I_((B + F)CF) 11.2 31.3 3.1 8.1

The data in Table 3 again demonstrate that conventional blended cementsmade by intergrinding all components together are suboptimal compared togap graded blends in which the three components are processed separatelyin order to provide fine, medium, and coarse fractions havingcomplementary PSDs. Nevertheless, although the gap graded blends ofComparative Examples 50-54 performed substantially better than theinterground blends of Comparative Examples 55-59, they only permittedthe use of 55% SCM and 45% Portland cement rather than 75% SCM and only25% Portland cement as in the gap graded blends of Examples ComparativeExamples 43-47.

Optimization Score—45% Cement, 55% SCM

Using the proposed analytical framework, it was determined that theternary blends of Comparative Examples 50-54 substantially, but notfully, comply with Principle 1 due to the smaller but still significantfraction of coarse cement particles (>24 μm). They partially comply withPrinciple 2 due to the existence of significant quantities of both veryfine cement and SCM particles (<8 μm). They comply with Principle 3because the high quantity of fine and coarse SCM particles broadens theoverall PSD of the blend to approach a Fuller distribution. Theestimated score is 3.0 (1.0+0.5+1.5), which explains why the ternaryblends of Comparative Examples 50-54 had higher SCM substitution (55%)compared to the binary blend of Comparative Example 19 (35%) having ascore of 2.5 but lower SCM substitution (55%) compared to the gap-gradedternary blends (75%) of Comparative Examples 43-47 with a scoreapproaching 4.0. The ternary blends of Comparative Examples 50-54 aretherefore suboptimal compared to the gap-graded ternary blends ofComparative Examples 43-47 because they contain a substantial quantityof “wasted cement” that is unavailable for making cement paste binderand also unavailable as a source of calcium ions for reacting withpozzolanically reactive materials in the blends.

Summary Of Findings

Based on the foregoing, it is proposed that the analytical framework andmethodology can be used to determine the permissible SCM content ofvirtually any blended cement by first determining its optimization scoreand then comparing it to the optimization scores of known cementsdetermined above, which are summarized in Table 4.

TABLE 4 Summary of optimization scores, SCM content, and OPC content SCMCement Optimization Cement Material Content Content Score OPC  0% 100% 1.0 Binary Blend 20% 80% 2.0 Binary Blend 35% 65% 2.5 Ternary Blend 55%45% 3.0 Ternary Blend 75% 25% 4.0

By way of illustration, it was determined that a simple 80:20 blend ofOPC and fly ash has an optimization score similar to OPC by itself(about 1.0). As a result, a cubic yard of concrete made using a simple80:20 blend of OPC (400 lbs.) and fly ash (100 lbs.) will typically havelower early strength than a cubic yard of concrete made using 500 lbs.of OPC and no fly ash at the same water to cementitious binder ratio(w/cm). In contrast, concrete made using a binary blend with anoptimization score of 2.0 will have the same or better early strength asconcrete made using 100% OPC.

An interground blend of 80% Portland cement and 20% SCM will typicallyyield concrete having better strength than the simple 80:20 blend of OPCand fly ash but with lower strength and/or higher water demand comparedto concrete made using 100% OPC at the same w cm. This can be explainedby interground blends having an optimization score of about 1.25-1.75.Intergrinding Portland cement and SCM can increase the score for one orboth of Principles 1 and 2 by an estimated 0.25-0.5 depending on therelative grinding characteristics of the Portland cement clinker and SCMmaterials and maintains or slightly lowers the score for Principle 3depending on the Blaine, which is often increased in interground blendscompared to OPC to increase reactivity and offset strength loss causedby the dilution of Portland cement with SCM.

The proposed analytical framework explains why, because of theoffsetting effects caused by increasing or decreasing the Blainerelative to Principles 1 and 3 (i.e., raising one necessarily lowers theother), little is gained by increasing Blaine to increase the strengthof interground blended cements. It also explains why interground blendedcements of very high Blaine, while highly reactive even at high SCMlevels, are nonetheless suboptimal because increasing the Principle 1score by reducing or eliminating coarse cement particles above 24 μmcauses a corresponding or greater decrease in the Principle 3 score bysignificantly or substantially narrowing the PSD, which increases waterdemand, shrinkage, and other negative features of overly fine cement.

Examples 60-64

Each of Comparative Examples 43-47 is modified by replacing the fine SCMfraction and the middle narrow PSD Portland cement fraction with a fineinterground particulate component formed by intergrinding the SCM andcement clinker materials used to make the fine and middle fractions ofeach of Comparative Examples 43-47 in a manner so as to have the samed90 as the middle cement fraction (e.g., 21.54 μm). The coarse fractionused in each of Comparative Examples 43-47 remains unchanged andconstitutes a coarse particulate component that is not interground withthe fine interground particulate component in Examples 60-64. Therelative quantities of the materials used to make the fine, middle, andcoarse particulate fractions in Comparative Examples 43-47 remain thesame such that the cement-SCM compositions of Examples 60-64 contain 36%of fine interground SCM material, 25% of fine interground cementmaterial (for a combined total of 61% interground materials), and 39% ofcoarse SCM material not interground with the fine intergroundparticulate component.

It is postulated that the cement-SCM compositions according to Examples60-64, when tested according to ASTM C-109 and made with the samewater-to-cementitious binder ratio (w/cm) as in each of ComparativeExamples 43-47, will have comparable 3- and 28-day compressive andflexural strengths, comparable water demand and flow, comparable HRWRrequirement, and comparable long-term durability compared to eachcorresponding Comparative Example 43-47.

It is postulated that the cement-SCM compositions according to Examples60-64 can perform as well or almost as well as the gap graded blends ofComparative Examples 43-47 relative to 3- and 28-day strengthdevelopment owing to the fact that Examples 60-64 do not include agreater quantity of coarse cement particles that do not fully hydratewithin 28 days as compared to the gap graded blends of ComparativeExamples 43-47. As result, the strength developing properties of thecement fraction should be similar in each of Comparative Examples 43-47and Examples 60-64. In addition, the amount of calcium ions released bythe cement component for promoting the pozzolanic reaction should besimilar.

And while it is possible that intergrinding the fine SCM fraction withcement as in Examples 60-64, rather than providing it as a separate finefraction as in Comparative Examples 43-47, may reduce somewhat thereactivity of the fine SCM fraction and reduce strength development, itis a worthwhile tradeoff since Examples 60-64 can be manufactured in anindustrially feasible manner, while Comparative Examples 43-47 arereportedly not industrially feasible. Even if the SCM substitutionlevels are reduced from the 75% level achieved in Comparative Examples43-47, such as to 70%, 65%, or even 60%, they would still besignificantly to substantially higher than the 55% substitution levelachieved in Comparative Examples 50-54, which is surprising andunexpected in view of current practices and knowledge.

Examples 65-69

Each of Comparative Examples 50-54 is modified by replacing the fine SCMfraction and the commercial Portland cement fraction with a fineinterground particulate component formed by intergrinding the SCM andcement clinker materials used to make the fine and middle fractions ofeach of Comparative Examples 50-54 in a manner so as to significantlyreduce the quantity of coarse cement particles that do not fully hydratewithin 28 days compared to commercial Portland cement. For example, thefine interground particulate component could be ground to the same orlower d90 as in Examples 60-64 (i.e., 21.54 μm). Alternatively, the d90can be raised to compensate for increased fineness that may result whenusing the fine interground particulate component in place of the fineSCM fraction and the commercial Portland cement used in ComparativeExamples 50-54 (e.g., the d90 of the fine interground particulatecomponent can be higher than 21.54 μm and less than the d90 of thecommercial Portland cement used in Examples 50-54, such as a d90 equalto or less than 42.5 μm, 40 μm, 37.5 μm, 35 μm, 32.5 μm, 30 μm, 27.5 μm,25 μm, or 23 μm).

The coarse SCM fraction used in each of Comparative Examples 50-54remains unchanged and constitutes a coarse particulate component that isnot interground with the fine interground particulate component. Therelative quantities of the materials used to make the fine, middle, andcoarse particulate fractions in Comparative Examples 50-54 remain thesame such that the cement-SCM compositions of Examples 65-69 contain 25%of fine interground SCM material, 45% of fine interground cementmaterial (for a combined total of 70% interground materials), and 30% ofcoarse SCM material not interground with the fine intergroundparticulate component.

The cement-SCM compositions according to Examples 65-69, when testedaccording to ASTM C-109 and made with the same water-to-cementitiousbinder ratio (w/cm) used in each of Comparative Examples 50-54, willhave higher 3- and 28-day compressive and flexural strengths, comparablewater demand and flow, comparable HRWR requirement, and higher long-termdurability compared to each corresponding Comparative Example 50-54.

It is postulated that the cement-SCM compositions according to Examples65-69 would perform better than the gap graded blends of ComparativeExamples 50-54 relative to 3- and 28-day strength development owing tothe fact that Examples 65-69 include a lower quantity of coarse cementparticles that do not fully hydrate within 28 days as compared to thegap graded blends of Comparative Examples 50-54, which use commercialPortland of standard fineness and PSD and are therefore believed to besuboptimal. As result, the strength developing properties of the cementfraction should be superior in Examples 65-69 compared to ComparativeExamples 50-54. In addition, the amount of calcium ions released by thecement component for promoting the pozzolanic reaction should besignificantly greater in Examples 65-69.

And while it is possible that intergrinding the fine SCM fraction withcement as in Examples 65-69, rather than providing it as a separate finefraction as in Comparative Examples 50-54, may reduce somewhat thereactivity of the fine SCM fraction and reduce strength developmentattributable to the pozzolanic reaction, it is postulated that theincreased reactivity of the fine cement fraction will more than offsetany strength reducing effect caused by the fine interground SCM fractioncompared to a separately processed fine SCM fraction as in Examples50-54. More particularly, it is postulated that increasing thereactivity of the more reactive component (cement) will cause a greaternet increase in total cement-SCM reactivity even if the reactivity ofthe less reactive component (pozzolan or other SCM) is reduced.

Because Examples 65-69 should provide higher 3- and 28-day strengthscompared to Comparative Examples 50-54, a manufacturer or user canchoose whether to make or use a cement-SCM composition having higherstrength, by keeping the relative cement and SCM proportions the same,increasing the level of SCM substitution while maintaining similarstrength, or some hybrid having both higher strength and higher SCMsubstitution. Providing a cement-SCM composition having superiorstrength should permit the use of less cement when making the samequantity of concrete having the same strength rating and which, allthings being equal, should reduce cost and lower the carbon footprint ofthe concrete. Alternatively, proving a cement-SCM composition havingsuperior strength would permit the use of additional SCM materials, suchas may be provided as an optional auxiliary particulate component.

Alternatively, it would be possible to create even higher strengthcement-SCM compositions by reducing the level of SCM substitution and/orby blending the cement-SCM compositions of Examples 65-69 with a morereactive hydraulic cement material, such as a more reactive cement-SCMcomposition made according to the present disclosure or a binary blendmade according to Comparative Examples 9, 14, or 17. The more reactivehydraulic cement material would constitute an optional auxiliaryparticulate component.

Finally, Examples 65-69 should provide substantially greater strength ascompared to the interground blended cements of Comparative Examples55-59, which have no particle size optimized cement or SCM componentsand are reflective of current commercial practices used to makeinterground blended cements. For one thing, Examples 65-69 contain fewercoarse cement particles that do not fully hydrate in 28 days compared tothe interground blends of Comparative Examples 55-59, making Examples65-69 more reactive relative to cement hydration. In addition, bygrinding the fine interground particulate component to a d90 that issubstantially lower than the d90 of OPC and conventional intergroundblended cements, the fine interground SCM components in Examples 65-69would be expected to be finer than the finer SCM fractions contained inComparative Examples 55-59, providing Examples 65-69 with higherpozzolanic reactivity (in the case of pozzolanic SCM) and/or cementnucleation potential (in the case of limestone or other non-reactiveSCM). Finally, the potentially lower reactivity of the coarse SCMcomponent in Examples 65-69 is more than offset by the higher reactivityof the fine interground cement fraction (and possibly also the higherreactivity of the fine SCM fraction).

Optimization Scores of Examples 60-69

Using the analytical framework, it was determined that the cement-SCMcompositions of Examples 60-69 should have an optimization score greaterthan 2.5 and may approach 4.0. The fine interground particulatecomponent can be ground so as to reduce, minimize, or eliminate coarsecement particles above 24 μm and substantially or fully comply withPrinciple 1. The fine SCM sub-fraction reduces the quantity of finecement particles below 8 μm compared to fine cement groundindependently, which increases (but may not fully reach) compliance withPrinciple 2. Intergrinding cement clinker with a soft SCM can reduce thepreponderance of fine cement particles below 8 μm in the fineinterground cement-SCM fraction and further increase compliance withPrinciple 2. Blending the fine interground particulate component withthe coarse particulate component substantially or fully complies withPrinciple 3. Depending on the level of compliance with Principles 1-3,it should be possible for cement-SCM compositions to have anoptimization score of 3.0 or higher, which should yield blended cementshaving the same or higher SCM level as the ternary blends of ComparativeExamples 50-54 (55%), which is surprising and unexpected in view ofcurrent practices and available knowledge.

It is also postulated that cement-SCM compositions as disclosed hereinmay permit SCM substitution levels of up to 75%, similar to the gapgraded ternary blends of Examples 43-47, while greatly simplifying themanufacture of cement-SCM blends and permitting their manufacture in anindustrially feasible manner, which is surprising and unexpected in viewof current practices and available knowledge.

It is also postulated that the cement-SCM compositions of Examples 21-38would permit the use of greater quantities of SCM in place of Portlandcement while also maintaining similar or greater strength as 100% OPCcompared to any of Comparative Examples 1-20.

Example 70

Any of Examples 60-69 is modified by replacing some or all of thePortland cement clinker with one or more hydraulic cements known in theart, including any of the hydraulic cements disclosed herein. Comparedto a control cementitious composition comprising hydraulic cement andpozzolan or other SCM, the modified cement-SCM compositions made using afine interground particulate component comprising a hydraulic cementfraction and an SCM fraction together with a coarse particulatecomponent comprising coarse SCM particles will achieve higher strengthcompared to the control cementitious composition.

Example 71

Any of Examples 60-70 is modified by replacing a portion of the pozzolanin the fine interground particulate component with an amount oflimestone sufficient to increase heat of hydration and/or early strengthof the cement-SCM composition. For example, to the extent that any ofExamples 60-70 has adequate long-term strength (e.g., similar to orhigher than a 100% control cement) but has inadequate early strength,adding finely ground limestone can beneficially increase early strengthwhen so desired. Because limestone may reduce long-term strength, theaddition of limestone will be more suitable for cement-SCM blends havinghigher long-term strength compared to the control cement. In such cases,an amount of limestone can be added that will reduce the long-termstrength to the same level as the control cement while beneficiallyincreasing early strength. In this way, the strength curve of themodified cement-SCM composition can more closely resemble the strengthcurve of the control cement compared to the cement-SCM blend devoid oflimestone.

Example 72

Any of examples 60-71 is modified by adding, without intergrinding withthe fine interground particulate component and the coarse particulatecomponent, one or more auxiliary particulate components known in the artand/or as disclosed herein in order to modify the properties of thecement-SCM composition. For example, one or more of silica fume, OPC,finely ground cement, blended cement, GGBFS, finely ground limestone, orfly ash can, without further modification, be combined with thecement-SCM composition of any of Examples 60-71 to form a modifiedcement-SCM composition having desired properties.

Example 73

Any of examples 60-72 is modified by adding an amount of a calcium-basedset accelerator, such as calcium oxide (CaO), calcium chloride (CaCl₂)),calcium nitrite (Ca(NO₂)₂, or calcium nitrate (Ca(NO₃)₂ and/or an alkalimetal salt capable of increasing the pH of the mix water, such as sodiumhydroxide (NaOH), sodium citrate, or other alkali metal salt of a weakacid. The calcium ions provided by the calcium-based set acceleratorwill not only accelerate hydration of the hydraulic cement fraction ofthe cement-SCM composition (e.g., in cold weather or other situationswhere it is desired to increase early strength), they can beneficiallyreact with silicate ions from the pozzolan to form additional cementbinder products. Alternatively, or in addition, the increased pHprovided by the alkali metal salt can accelerate the pozzolanic reactionby accelerating dissolution of silicate ions and/or aluminate ions fromthe pozzolan and making them more readily available for reaction withcalcium and/or magnesium ions provided by the hydraulic cement fraction.

Example 74-40% SCM Substitution

A cement-SCM composition comprising 60% hydraulic cement and 40% SCM ismanufactured as follows. A fine interground particulate component ismanufactured by intergrinding in a mill, such as a vertical roller mill,360 parts by weight of Portland cement clinker and 90 parts by weight ofSCM to a d90=25 μm±2 μm, as measured using a standard PSD measuringdevice, which yields 450 parts by weight of the fine intergroundparticulate component. The SCM used to make the fine intergroundparticulate component may primarily or exclusively comprise one or morepozzolans (e.g., slag, natural pozzolan, and/or coal ash), but mayoptionally include limestone or other filler material in addition to theone or more pozzolans. The quantity of cement clinker and/or SCM used tomake the fine interground particulate component can be adjusted toaccount for moisture loss during the intergrinding process and/or topermit the inclusion of a quantity of gypsum to yield a properly sulfatebalanced cement-SCM composition (after blending). Gypsum may beconsidered to form part of the cement component, the SCM component, orboth (e.g., prorated between the two).

The 450 parts of fine interground particulate component is blended with150 parts of a coarse SCM component having a d90=75 μm±10 μm, asmeasured using a standard PSD measuring device, to yield 600 parts ofthe cement-SCM composition. The coarse SCM component may primarily orexclusively comprise one or more pozzolans (e.g., slag, naturalpozzolan, and/or coal ash), but may optionally include limestone orother filler material in addition to, or instead of, the one or morepozzolans.

The 360 parts of Portland cement clinker (optionally including gypsum)constitutes 60% of the 600 parts of total cement-SCM composition. The 90parts of SCM in the fine interground particulate component and the 150parts of SCM in the coarse SCM component total 240 parts, whichconstitutes 40% of the 600 parts of total cement-SCM composition.

The cement-SCM composition, when tested according to ASTM C-109 andcompared to 100% OPC made from the same Portland cement clinker used tomake the fine interground particulate component, has a compressivestrength that is at least 90% of the compressive strength of the 100%OPC, when tested according to ASTM C-109 at the same w cm as thecement-SCM composition, at 1 day, 3 days, 7 days, and 28 days.

Example 75-50% SCM Substitution

A cement-SCM composition comprising 50% hydraulic cement and 50% SCM ismanufactured as follows. A fine interground particulate component ismanufactured by intergrinding in a mill, such as a vertical roller mill,300 parts by weight of Portland cement clinker and 130 parts by weightof SCM to a d90=22 μm±2 μm, as measured using a standard PSD measuringdevice, which yields 430 parts by weight of the fine intergroundparticulate component. The SCM used to make the fine intergroundparticulate component may primarily or exclusively comprise one or morepozzolans (e.g., slag, natural pozzolan, and/or coal ash), but mayoptionally include limestone or other filler material in addition to theone or more pozzolans. The quantity of cement clinker and/or SCM used tomake the fine interground particulate component can be adjusted toaccount for moisture loss during the intergrinding process and/or topermit the inclusion of a quantity of gypsum to yield a properly sulfatebalanced cement-SCM composition (after blending). Gypsum may beconsidered to form part of the cement component, the SCM component, orboth (e.g., prorated between the two).

The 430 parts of fine interground particulate component is blended with170 parts of a coarse SCM component having a d90=75 μm±8 μm, as measuredusing a standard PSD measuring device, to yield 600 parts of thecement-SCM composition. The coarse SCM component may primarily orexclusively comprise one or more pozzolans (e.g., slag, naturalpozzolan, and/or coal ash), but may optionally include limestone orother filler material in addition to, or instead of, the one or morepozzolans.

The 300 parts of Portland cement clinker (optionally including gypsum)constitutes 50% of the 600 parts of total cement-SCM composition. The130 parts of SCM in the fine interground particulate component and the170 parts of SCM in the coarse SCM component total 300 parts, whichconstitutes 50% of the 600 parts of total cement-SCM composition.

The cement-SCM composition, when tested according to ASTM C-109 andcompared to 100% OPC made from the same Portland cement clinker used tomake the fine interground particulate component, has a compressivestrength that is at least 90% of the compressive strength of the 100%OPC, when tested according to ASTM C-109 at the same w cm as thecement-SCM composition, at 1 day, 3 days, 7 days, and 28 days.

Example 76-60% SCM Substitution

A cement-SCM composition comprising 40% hydraulic cement and 60% SCM ismanufactured as follows. A fine interground particulate component ismanufactured by intergrinding in a mill, such as a vertical roller mill,240 parts by weight of Portland cement clinker and 170 parts by weightof SCM to a d90=20 μm±2 μm, as measured using a standard PSD measuringdevice, which yields 410 parts by weight of the fine intergroundparticulate component. The SCM used to make the fine intergroundparticulate component may primarily or exclusively comprise one or morepozzolans (e.g., slag, natural pozzolan, and/or coal ash), but mayoptionally include limestone or other filler material in addition to theone or more pozzolans. The quantity of cement clinker and/or SCM used tomake the fine interground particulate component can be adjusted toaccount for moisture loss during the intergrinding process and/or topermit the inclusion of a quantity of gypsum to yield a properly sulfatebalanced cement-SCM composition (after blending). Gypsum may beconsidered to form part of the cement component, the SCM component, orboth (e.g., prorated between the two).

The 410 parts of fine interground particulate component is blended with190 parts of a coarse SCM component having a d90=75 μm±8 μm, as measuredusing a standard PSD measuring device, to yield 600 parts of thecement-SCM composition. The coarse SCM component may primarily orexclusively comprise one or more pozzolans (e.g., slag, naturalpozzolan, and/or coal ash), but may optionally include limestone orother filler material in addition to, or instead of, the one or morepozzolans.

The 240 parts of Portland cement clinker (optionally including gypsum)constitutes 40% of the 600 parts of total cement-SCM composition. The170 parts of SCM in the fine interground particulate component and the190 parts of SCM in the coarse SCM component total 360 parts, whichconstitutes 60% of the 600 parts of total cement-SCM composition.

The cement-SCM composition, when tested according to ASTM C-109 andcompared to 100% OPC made from the same Portland cement clinker used tomake the fine interground particulate component, has a compressivestrength that is at least 90% of the compressive strength of the 100%OPC, when tested according to ASTM C-109 at the same w cm as thecement-SCM composition, at 1 day, 3 days, 7 days, and 28 days.

Example 77-70% SCM Substitution

A cement-SCM composition comprising 30% hydraulic cement and 70% SCM ismanufactured as follows. A fine interground particulate component ismanufactured by intergrinding in a mill, such as a vertical roller mill,180 parts by weight of Portland cement clinker and 180 parts by weightof SCM to a d90=15 μm±2 μm, as measured using a standard PSD measuringdevice, which yields 360 parts by weight of the fine intergroundparticulate component. The SCM used to make the fine intergroundparticulate component may primarily or exclusively comprise one or morepozzolans (e.g., slag, natural pozzolan, and/or coal ash), but mayoptionally include limestone or other filler material in addition to theone or more pozzolans. The quantity of cement clinker and/or SCM used tomake the fine interground particulate component can be adjusted toaccount for moisture loss during the intergrinding process and/or topermit the inclusion of a quantity of gypsum to yield a properly sulfatebalanced cement-SCM composition (after blending). Gypsum may beconsidered to form part of the cement component, the SCM component, orboth (e.g., prorated between the two).

The 360 parts of fine interground particulate component is blended with240 parts of a coarse SCM component having a d90=75 μm±10 μm and ad10=15 μm±5 μm, as measured using a standard PSD measuring device, toyield 600 parts of the cement-SCM composition. The coarse SCM componentmay primarily or exclusively comprise one or more pozzolans (e.g., slag,natural pozzolan, and/or coal ash), but may optionally include limestoneor other filler material in addition to, or instead of, the one or morepozzolans. The coarse SCM component can be dedusted to remove fines inorder to raise the d10 to the specified value or range. The dedustedfines can be used as a premium SCM material in other cement or concreteand/or as at least a portion of the SCM used to make the fineinterground component.

The 180 parts of Portland cement clinker (optionally including gypsum)constitutes 30% of the 600 parts of total cement-SCM composition. The180 parts of SCM in the fine interground particulate component and the240 parts of SCM in the coarse SCM component total 420 parts, whichconstitutes 70% of the 600 parts of total cement-SCM composition.

The cement-SCM composition, when tested according to ASTM C-109 andcompared to 100% OPC made from the same Portland cement clinker used tomake the fine interground particulate component, has a compressivestrength that is at least 90% of the compressive strength of the 100%OPC, when tested according to ASTM C-109 at the same w cm as thecement-SCM composition, at 1 day, 3 days, 7 days, and 28 days.

Examples 78-80

Concrete mixes were made using a standard rotary concrete mixer obtainedfrom Harbor Freight. Fresh concrete was cast into 4×8 inch cylinders andtested by CMT Engineering in West Valley City, Utah. The fineinterground cement-SMC fraction was made by intergrinding Drake clinkerand Drake pozzolan in a ratio of 1:1 to a d90 of 24 μm in a bench-scalevertical roller mill at Gebr. Pfeiffer, Kaiserslautern, Germany. Plasterof Paris was added to provide 2.3% sulfate (SO₃). Coarse quarry finescontaining at least about 90% limestone in the form of calcite andhaving an average particle size of about 75 μm were purchased fromStaker-Parson and produced in Genola, Utah at a limestone quarry. Coarseand fine aggregates were purchased from Staker-Parson and produced inNorth Salt Lake, Utah. The concrete mixes were based on a common “6-bag”concrete mix with a design strength at 28 days of 5200 psi (Example 78).The concrete mixes are expressed in terms of the quantities required tomake a cubic yard of concrete and are set forth in Table 1. Suitablelignosulfonate (Plastocrete 161) and/or polycarboxylate ether(Viscocrete 2100) were used to maintain desired slump between about 3-6inches.

The concrete mixes are expressed in terms of the quantities required tomake a cubic yard of concrete and are set forth in Table 5.

TABLE 5 Components/Compressive Example Strength 78 79 80 Type I/II OPC(lb.) 564 0 0 Interground cement (lb.) 0 540.85 721.13 Quarry Fines(lb.) 56.4 112.8 112.8 Plaster of Paris (lb.) 0 23.4 30.87 Type S Lime(lb.) 0 11.28 11.28 Coarse Aggregate (lb.) 1750 1704 1600 Fine Aggregate(lb.) 1372 1205 1175 Water (lb.) 266.6 270.38 251.88 w/cm 0.47 0.47 0.33w/c 0.47 0.94 0.66  3-day (psi) 3850 3590 2390  7-day (psi) 4580 46204970 28-day (psi) 5690 5830 6970 91-day (psi) n/a 6750 9000 182-day(psi)  n/a 7090 10540

As shown in Table 5, the concrete made with fine intergroundcement-pozzolan and quarry fines exhibited impressive strength given thelow clinker content and relatively high water used in Example 79.Example 80 made at much lower water was retarded using citric acid (0.2%by weight of interground cement), which reduced early strength butultimately yielded very high strength.

Example 81

Any of the foregoing examples is modified by utilizing a raw feed forcement kiln, such as the raw feed utilized at the Devils Slide, Utah,cement plant, as coarse SCM blending component. For example, acement-SCM blend is made in the following steps: (1) producing a fineinterground particulate component by intergrinding cement clinker,pozzolan, gypsum, and optionally limestone in a cement mill, such as aball mill, vertical roller mill, or horizontal roll press; (2) producinga raw feed for a cement kiln by grinding together a calcareous feed(e.g., limestone) and argillaceous feed (e.g., one or more of clay,shale, iron ore, or other mineral) in a mill (e.g., vertical roller millor Raymond mill); (3) removing a side stream of the raw feed; and (4)blending the fine interground particulate component with the side streamof the raw feed.

Alternatively, the raw feed can be blended with the fine intergroundparticulate component in a concrete mixer together with water,aggregates, and optionally one or more chemical admixtures.

Example 82

Any of the foregoing examples is modified by utilizing shale flue dustas coarse SCM blending component. such as the shale flue dust producedas byproduct by the Utelite lightweight aggregate plan in Coalville,Utah. For example, a cement-SCM blend is made in the following steps:(1) producing a fine interground particulate component by intergrindingcement clinker, pozzolan, gypsum, and optionally limestone in a cementmill, such as a ball mill, vertical roller mill, or horizontal rollpress; (2) collecting shale flue dust produced as a byproduct whencalcining shale aggregates in a kiln; and (3) blending the fineinterground particulate component with the shale flue dust.

Alternatively, the shale flue dust can be blended with the fineinterground particulate component in a concrete mixer together withwater, aggregates, and optionally one or more chemical admixtures.

Example 83

Any of the foregoing examples is modified by utilizing mine tailings ascoarse SCM blending component. such as the mine tailings produced by RioTinto, Utah, from the Bingham copper mine operation. For example, acement-SCM blend is made in the following steps: (1) producing a fineinterground particulate component by intergrinding cement clinker,pozzolan, gypsum, and optionally limestone in a cement mill, such as aball mill, vertical roller mill, or horizontal roll press; (2)collecting mine tailing produced as a byproduct of copper manufacture(e.g., removing mine tailings from the large mountain of tailingsadjacent to I-80 near Magna, Utah); (3) optionally modifying the minetailings to control particle size by one or more of screening, milling,or classifying in air classifier; and (4) blending the fine intergroundparticulate component with the mine tailings.

Alternatively, the mine tailings can be blended with the fineinterground particulate component in a concrete mixer together withwater, aggregates, and optionally one or more chemical admixtures.

Example 84

Any of the foregoing examples is modified by utilizing ground recycledconcrete as coarse SCM blending component, such as may be recovered fromdestroyed concrete structures and/or produced in excess at a job site.For example, a cement-SCM blend is made in the following steps: (1)producing a fine interground particulate component by intergrindingcement clinker, pozzolan, gypsum, and optionally limestone in a cementmill, such as a ball mill, vertical roller mill, or horizontal rollpress; (2) grinding recovered waste concrete using a mill and optionallya classifier in a grinding circuit; and (3) blending the fineinterground particulate component with the ground waste concrete.

Alternatively, the ground waste concrete can be blended with the fineinterground particulate component in a concrete mixer together withwater, aggregates, and optionally one or more chemical admixtures.

Example 85

Any of the foregoing examples is modified by utilizing washout fines ascoarse SCM blending component, such as may be recovered when washing outthe mixing bucket of concrete trucks. For example, a cement-SCM blend ismade in the following steps: (1) producing a fine intergroundparticulate component by intergrinding cement clinker, pozzolan, gypsum,and optionally limestone in a cement mill, such as a ball mill, verticalroller mill, or horizontal roll press; (2) recovering washout fines fromleftover concrete; (3) drying the washout fines (e.g., by placing themin a pile for air drying and/or running them through a heater); and (4)blending the fine interground particulate component with the washoutfines.

Alternatively, the washout fines can be blended with the fineinterground particulate component in a concrete mixer together withwater, aggregates, and optionally one or more chemical admixtures. Insuch case, it may not be necessary to fully dry the washout finesalthough the amount of water remaining the fines will need to beaccounted for to produce concrete with a desired water to cement ratio.

Example 86

Any of the foregoing examples is modified by utilizing quarry finesproduced as a byproduct from aggregate manufacture as coarse SCMblending component. For example, a cement-SCM blend is made in thefollowing steps: (1) producing a fine interground particulate componentby intergrinding cement clinker, pozzolan, gypsum, and optionallylimestone in a cement mill, such as a ball mill, vertical roller mill,or horizontal roll press; (2) recovering quarry fines from aggregates;(3) optionally milling the quarry fines to a desired particle size orsize range; and (4) blending the fine interground particulate componentwith the quarry fines.

Alternatively, the quarry fines can be blended with the fine intergroundparticulate component in a concrete mixer together with water,aggregates, and optionally one or more chemical admixtures. In suchcase, it may not be necessary to mill the quarry fines as long as theyare properly apportioned between cement replacement and fine aggregatereplacement. For a better understanding of how to properly apportionquarry fines between cement and aggregate replacement, reference is madeto U.S. Pat. Nos. 10,131,575; 10,730,805; and 10,737,980, which areincorporated herein by reference.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

1. A method of manufacturing an activated pozzolan composition,comprising: grinding a natural pozzolan, alone or with another mineralcomponent that is not cement clinker, to form a finely ground pozzolancomponent having a first d90 in a range of about 10 μm to about 45 μmand a first d10 less than about 5 μm; and blending, withoutintergrinding, the finely ground pozzolan component with a coarseparticulate mineral component comprised of coarse mineral particles notinterground with the fine interground particulate component, the coarseparticulate component having a second d90 greater than the first d90 anda second d10 greater than the first d10.
 2. The method of claim 1,wherein the natural pozzolan is selected from natural pozzolanicdeposits, volcanic ash, metakaolin, shale dust, calcined clay, trass,pumice, and combinations thereof.
 3. The method of claim 1, whereingrinding the natural pozzolan includes intergrinding the naturalpozzolan with the other mineral component to form the finely groundpozzolan component, wherein the other mineral component is selected fromthe group consisting of slags, glass, bottom ash, and non-pozzolanicmaterials.
 4. The method of claim 3, wherein the slags are selected fromground granulated blast furnace slag, steel slag, and metallurgical slagcontaining amorphous silica, the glass is selected from post-consumerglass and industrial waste glass, and the non-pozzolanic materials areselected from limestone, clay, calcium carbonate produced by reactingCO₂ from an industrial source and calcium ions, precipitated calciumcarbonate, crystalline minerals, quartz, waste fines from aggregateprocessing, ground geologic materials, quarry fines, shale dust, minetailings, concrete washout fines, red mud, and ground waste concrete. 5.The method of claim 1, wherein the first d90 of the finely groundpozzolan component is in a range of about 15 μm to about 35 μm.
 6. Themethod of claim 1, wherein the coarse particulate mineral component hasa d10 equal to or greater than about 3 μm and a d90 equal to or greaterthan about 35 μm and less than about 300 μm.
 7. The method of claim 1,wherein the coarse particulate mineral component has a d90 in a range ofabout 50 μm to about 150 μm.
 8. The method of claim 1, wherein thefinely ground pozzolan component and the coarse particulate mineralcomponent are dry blended to form a dry particulate blend.
 9. The methodof claim 1, wherein the coarse particulate mineral component comprisedof coarse SCM particles not interground with the fine intergroundparticulate component comprises two or more different types ofmaterials.
 10. The method of claim 3, wherein the mineral componentinterground with the natural pozzolan to form the finely ground pozzolancomponent and/or the coarse particulate mineral component notinterground with the finely ground pozzolan component is/are selectedfrom the group consisting of coal ashes, slags, natural pozzolans,ground glass, non-pozzolanic materials, fly ash, bottom ash, groundgranulated blast furnace slag, steel slag, metallurgical slag containingamorphous silica, natural pozzolanic deposits, volcanic ash, metakaolin,shale dust, calcined clay, trass, pumice, post-consumer glass,industrial waste glass, limestone, metastable calcium carbonate producedby reacting CO₂ from an industrial source and calcium ions, precipitatedcalcium carbonate, crystalline minerals, clay, ores, mine tailings,ground shale, hydrated cements, waste concrete, ground recycledconcrete, washout fines, tuff, trass, geologic materials, waste glass,glass shards, basalt, sinters, ceramics, recycled bricks, recycledconcrete, refractory materials, other waste industrial products, sand,raw feed for cement kilns, and natural minerals.
 11. An activatedpozzolan composition manufactured according to a method comprising:grinding a natural pozzolan, alone or with another mineral componentthat is not cement clinker, to form a finely ground pozzolan componenthaving a first d90 in a range of about 10 μm to about 45 μm and a firstd10 less than about 5 μm; and blending, without intergrinding, thefinely ground pozzolan component with a coarse particulate mineralcomponent comprised of coarse mineral particles not interground with thefine interground particulate component, the coarse particulate componenthaving a second d90 greater than the first d90 and a second d10 greaterthan the first d10.
 12. The method of claim 11, wherein the naturalpozzolan is selected from natural pozzolanic deposits, volcanic ash,metakaolin, shale dust, calcined clay, trass, pumice, and combinationsthereof.
 13. The activated pozzolan composition of claim 11, whereingrinding the natural pozzolan includes intergrinding the naturalpozzolan with the other mineral component to form the finely groundpozzolan component, wherein the other mineral component is selected fromthe group consisting of slags, glass, bottom ash, and non-pozzolanicmaterials.
 14. The activated pozzolan composition of claim 13, whereinthe slags are selected from ground granulated blast furnace slag, steelslag, and metallurgical slag containing amorphous silica, the glass isselected from post-consumer glass and industrial waste glass, and thenon-pozzolanic materials are selected from limestone, clay, calciumcarbonate produced by reacting CO₂ from an industrial source and calciumions, precipitated calcium carbonate, crystalline minerals, quartz,waste fines from aggregate processing, ground geologic materials, quarryfines, shale dust, mine tailings, concrete washout fines, red mud, andground waste concrete.
 15. The activated pozzolan composition of claim11, wherein the first d90 of the finely ground pozzolan component is ina range of about 15 μm to about 35 μm.
 16. The activated pozzolancomposition of claim 11, wherein the coarse particulate mineralcomponent has a d10 equal to or greater than about 3 μm and a d90 equalto or greater than about 35 μm and less than about 300 μm.
 17. Theactivated pozzolan composition of claim 11, wherein the coarseparticulate mineral component has a d90 in a range of about 50 μm toabout 150 μm.
 18. The activated pozzolan composition of claim 11,wherein the finely ground pozzolan component and the coarse particulatemineral component are dry blended to form a dry particulate blend. 19.The activated pozzolan composition of claim 11, wherein the coarseparticulate mineral component comprised of coarse SCM particles notinterground with the fine interground particulate component comprisestwo or more different types of materials.
 20. The activated pozzolancomposition of claim 13, wherein the mineral component interground withthe natural pozzolan to form the finely ground pozzolan component and/orthe coarse particulate mineral component not interground with the finelyground pozzolan component is/are selected from the group consisting ofcoal ashes, slags, natural pozzolans, ground glass, non-pozzolanicmaterials, fly ash, bottom ash, ground granulated blast furnace slag,steel slag, metallurgical slag containing amorphous silica, naturalpozzolanic deposits, volcanic ash, metakaolin, shale dust, calcinedclay, trass, pumice, post-consumer glass, industrial waste glass,limestone, metastable calcium carbonate produced by reacting CO₂ from anindustrial source and calcium ions, precipitated calcium carbonate,crystalline minerals, clay, ores, mine tailings, ground shale, hydratedcements, waste concrete, ground recycled concrete, washout fines, tuff,trass, geologic materials, waste glass, glass shards, basalt, sinters,ceramics, recycled bricks, recycled concrete, refractory materials,other waste industrial products, sand, raw feed for cement kilns, andnatural minerals.